Fun Animal Facts

Our random animal facts are a both fun and a little bit weird but they will keep you entertained for days!

WTF Fun Fact 12812 – The Mating Calls of Female Sloths

One thing we all know about sloths is that they’re slow. In fact, it’s pretty rare to witness a sloth moving at all, much less making the effort to mate. But female sloths have found a solution that allows them to find a partner with relatively little effort – screaming.

The sex of sloths

Three-fingered sloths, in particular, are hard to tell apart when it comes to determining their sex. According to Sloth Conservation (cited below) “Both sexes have a shaggy black mane around their necks. The appearance of the mane is unique to each individual, and it is not currently obvious if there is any sexual dimorphism in regards to its appearance.”

That doesn’t mean two-fingered sloths are any easier to tell apart. “In two-fingered sloths, distinguishing between males and females is notoriously difficult. This has led to some embarrassing mistakes at zoos and rescue centers, where two sloths thought to be of the same sex have been put into the same enclosure, only to produce a newborn baby some months later!”

The mating female sloth

One way you can tell male and female sloths apart is their mating behavior. It’s unknown if sloths have a specific mating season, but they’re fertile for about one week out of every month. And they let everyone know about it!

While their activity level increases during fertile periods, it’s mostly to produce vocalizations. Female sloths don’t walk around looking for mates – they sit in trees and scream incredibly loud to let males know they’re “available.”

The Sloth Conservation Foundation confirms: “These vocalizations, or “screams”, sound like bird calls or shrill whistles. She will do this for eight to ten days every single month, with the vocalizations increasing in frequency until she is screaming every 10 to 15 minutes. The male three-fingered sloths get very excited when they hear this call and will go in search of the female making it.”

Sound a lot easier than dating! – WTF fun facts

Source: “Sloth Mating: Not as slow as you think” — Sloth Conservation

WTF Fun Fact 12810 – The Platypus Has No Nipples

Platypus nipples are probably not the first thing that comes to mind when you think of interesting animal facts. But the fact that the creature has none is actually pretty wild.

We might think of nipples as something less than wholesome, but they serve a purpose – to feed the young.

How does a platypus feed their young without nipples?

In what may be one of nature’s strangest oversights, platypuses so have a milk duct, they do produce milk from their young, but there’s so central “outlet” from which to feed.

And while it’s bizarre to picture (but we swear this is how it works), the mothers secrete milk through their mammary glands, and it then rolls down their skin, collecting in the little grooves on their bodies. And that’s where their young find it to feed. In cases where there are patches of fur, the babies simply suck the milk out of those soaked fur patches.

It seems…less than efficient. But the platypus still exists, so it must work just fine for their species!

Platypus birth is also unique

The platypus is a monotreme – a creature in which reproduction takes place by females laying eggs. That might not seem like a big deal, but these are mammals. So it’s actually incredibly rare. Vertebrates (which are animals like birds, fish, reptiles, etc. all lay eggs), but the platypus and echidna (or spiny anteater) are the only common mammals that do it.  

When it’s born, the baby platypus cuts its way out of the egg using an “egg tooth” that grows on the end of its nose. This “tooth” is made of keratin (just like fingernails), and it falls off not long after.

Other fun facts about the platypus

According to the American Museum of Natural History (cited below), other fun facts about the platypus include:

“A female platypus usually lays only two eggs at a time and rarely leaves her stream-side den while nursing her young. When she does leave, she plugs the den opening with dirt.”

and…

“A platypus’s bill can sense tiny electric currents produced by the bodies of small animals, helping it hunt in muddy water.”

To be honest, we never gave much thought to the platypus. They’re not much to look at (though some might say they’re cute), but they’re certainly interesting from a biological standpoint!

– WTF fun facts

Source: “Platypus” – The American Museum of Natural History

WTF Fun Fact 12808 – Mourning Geckos Are All Female

Nearly every mourning gecko ever born has been a female. In fact, the species does not need males at all since the females are parthenogenic, meaning they can reproduce on their own. The female geckos can basically produce semi-clones of themselves to keep the species going.

Characteristics of the mourning gecko

These small lizards look a bit “warty,” but they’re an incredible species. However, it’s pretty rare to see one outside an aquarium. They’re native to southeast Asia, and while they occur throughout the Americas, Australia, and the Pacific islands, they are nocturnal creatures (though they are drawn to walls near artificial lights).

Gecko reproduction

So, what’s parthenogenesis? It simply means females can reproduce on their own, and there are a few different species that can do it (some crabs, snails, and the komodo dragons, for example).

In the case of the mourning geckos, they lay one to two eggs every two to four weeks over the course of their five-year lifespans. The eggs are laid in communal nesting spots and hatch 50 – 75 days later. The baby geckos are able to lay their own eggs after about eight months.

Female geckos clone themselves, in a way. All of the genetic material in the egg comes from them, but they are able to recombine their DNA to produce some genetic variation.

That explains why occasionally males are born. But the males are infertile, so they don’t serve much of a purpose to the species.

The problem with cloning

The downside of cloning yourself is that you have a limited amount of genetic material to work with. If a gene mutation exists, all of the progeny will have it.

If one of those mutations turned out to be fatal, it could spread through a population quickly and threaten its future.

Other cool gecko facts

Females can display courtship-like behavior, despite the species having no need for mating. The little lizards bob their heads and use sounds to communicate.

Oh, and they clean out their eyes with their tongues and shed their tails if they’re being captured.

– WTF fun facts

Source: “Mourning Gecko” — Georgia Aquarium

WTF Fun Fact 12807 – Snails Have Teeth

Have you ever wondered how a snail eats? We sure haven’t! But it turns out that snails have teeth laid out along their tongues – thousands of them, in fact.

Snail “teeth”

Snails have teeth, but they’re nothing like human teeth. First, the rows of minuscule teeth are laid out on their tongues. (We never really thought about whether snails had tongues either, to be honest).

According to Dr, Gordon Port, senior lecturer at Newcastle University: “A snail will use its toothy tongue ­– called the radula – almost like a file, scraping off the softer parts of their food when eating. Their teeth normally get worn down by this action, so they’re replaced regularly.”

A “toothy tongue”

BBC Science Focus (cited below) describes some of the variations on these “toothy tongues:”

“There are also some (downright terrifying) radula variations. Species such as cone snails – that are mainly found in warm and tropical waters – have a venomous radula that is used to paralyse prey before eating.

In case you’re wondering, slugs also have a radula, which similarly are fitted with thousands of tiny teeth. Some predatory slugs, such as the Welsh ghost slug, have radulae with razor-sharp teeth – each about half a millimetre long – that are used to kill and eat earthworms.

Many squids also have a radula inside their mouth. As its throat passes directly through the brain, a squid’s toothy tongue is needed to break down food into tiny pieces. Because, let’s face it, a piece of crab knocking against your brain is bound to ruin supper.”

What do snails eat?

Snails eat at night for the most part – which we’re grateful for, since they sound like pretty messy eaters.

And Port told BBC that they’ll eat just about any organic matter, like young plants. “And some species, such as Moon snails, are even known to eat each other. But, mostly, any decomposing matter will do.”

As long as snails aren’t chewing your foliage, they can be good for gardens since they eat decomposing matter and then serve as food for other animals.

– WTF fun facts

Source: “Do snails have teeth?” — BBC Science Focus

WTF Fun Fact 12806 – Greenland Sharks Are Blind

There are an awful lot of people who want to know “Are Greenland sharks blind?” That’s probably because any time you hear about the species Somniosus microcephalus it’s in relation to the parasite that lives in their eyes.

So, ARE Greenland sharks blind?

While we don’t know exactly what percent of Greenland sharks are blind, scientists do believe that many, if not most, at at least partially blind because of the parasites.

And these sharks already had a bad reputation to begin with. According to Oceana (cited below), “Like many other polar fish, their flesh contains high concentrations of natural antifreeze. According to a handful of reports, Greenland shark meat is so toxic it can make sled dogs vomit and ravens act drunk.”

But people aren’t big shark fans anyway, so their toxicity is very likely overstated. Oceana continues: “But this is likely a case of false advertising. The antifreeze compound in their tissue is toxic, but only mildly — an adult would have to eat around 20 kilograms (44 pounds) of shark at one sitting just to feel woozy.”

Ok, we’re blaming you if you eat that much shark meat.

Anyway, back to the blindness.

The sharks tend to be seen as ungraceful (the word “bumbling” has been used to describe them). But they’re born with small eyes to begin with and then lose their vision due to the parasitic crustaceans which measure just 3-centimeter-long – Ommatokoita elongata. Oceana states that “Each eye usually hosts one adult female along with several larvae. They nibble away at the shark’s cornea tissue, destroying its vision in the process.”

As a result, the sharks see in a haze and can only sense patterns of darkness and light.

However, they have a keen sense of smell, so they don’t have too much trouble grabbing dinner.

And dinner for this shark, which is a scavenger, is rotting meat.

Why do these sharks get such a bad rap?

Aside from looking kind of gross with the whole “crustacean feasting on their eyes” thing going on and harboring toxic chemicals in their skin, the sharks have a reputation as one of the “laziest” creatures.

Frankly, we’d prefer a lazy shark to a really energetic go-getter!

They get this reputation in part because the Greenland shark isn’t very fast (not surprising since they’re partially blind) as well as one of the world’s biggest sharks (reaching 24 feet long).

Somniosus microcephalus moseys along at around 1.5 miles an hour. But that’s also in part because of the frigid waters they live in. They are perfectly happy to live their lives in water as cold as 29 degrees F.

– WTF fun facts

Source: “Maligned as Lazy and Toxic, Greenland Sharks Are Smarter than You Think” — Oceana

WTF Fun Fact 12805 – Hummingbirds Can Fly Backward

“Can hummingbirds fly backwards?” is a fairly common Google query when it comes to these little creatures. And we have to admit, we never really thought about a bird’s ability to fly in different directions.

But the answer is yes. And, in fact, they’re the only birds that have the ability to fly backwards for any significant length of time. Flycatchers, warblers, and herons can move backwards, but only as a defensive maneuver.

Hummingbird flying skills – backward, forward, side to side

According to the Audobon Society (cited below), “The hummingbird is the only bird that can truly hover. It manages this by flapping its wings 20 to 80 times a second. It can fly straight up and down. Backwards and forwards. Or upside down. And up to 75 miles an hour. But don’t worry, it won’t run into you. This bird can slow down from 25 miles an hour to a dead stop in a space no longer than your index finger.”

It’s the bird’s unique muscle structure in their wings that allows them to fly this way. For example, they have a rotator cuff that allows them to move their wings in a figure-8 pattern.

The trade-off is that they have very weak legs. They can only hop short distances – and not very well. So they fly just about everywhere.

Fun facts about hummingbirds

Some other interesting things about hummingbirds that contribute to their uniqueness include:

  • Their ability to beat their wings up to 200 times per second. (This is especially the case in the smallest hummingbird species with the smallest wingspans – they need to move fast to stay aloft.)
  • The average speed of a hummingbird is 30 mph. That’s part of the reason they’re so hard to capture on camera.
  • The average hummingbird can consume twice its weight in sugar, which is needs to have the energy to power its flight.
  • Hummingbirds have around 1000 to 1500 feathers. And while that may sound like a lot, it’s significantly less than other birds. And that makes them more lightweight (a ruby throated hummingbird, for example, weighs just three grams).
  • Hummingbirds migrate from the east coast of the US to Central America each year, 1300-mile journey. It’s believed they can fly up to 500 miles in one day.

If you see a chubby hummingbird, it’s likely ready to begin its migration journey. The little creatures gain around 20 to 40% more body fat before they begin their annual migrations.

Since they live for around 5 years (though a few have been known to live to 11 or 12 years), they make the long trip more than a few times in their lives.

– WTF fun facts

Source: “Hummingbird Flight Is Like Nothing Else in the Bird World” — Audobon Society

WTF Fun Fact 12804 – Are Crocodiles Immortal?

No less a scientist than world-renowned physicist Dr. Michio Kaku has pondered the question “Are crocodiles immortal?” Of course, they’re not. But they’re still fascinating in terms of their lifespan – or lack thereof.

If crocodiles aren’t immortal, what’s the deal?

Crocodiles don’t have a formally recognized lifespan. In fact, they tend to outlive our interest in trying to figure it out at any given time. They can certainly live to be over 100, and they’re just as vigorous at that age as they are when they’re younger.

The only real difference is that they get bigger. But getting bigger can be a problem – it means they need to eat more and are at risk for starvation. And while they might not age biologically, the longer you live the greater your chances are of being killed by disease or accident. And those are the three main killers of crocodiles.

Not older, just bigger

According to an article by VICE (cited below) on crocodiles’ supposed immortality: “This is the reason we don’t happen to see crocodiles the size of Boeing 747s in the wild. Dr. Kaku also claims the standard 70-year crocodile lifespan defined by textbooks is basically because ‘zookeepers die at 70.'”

After talking to Billy Collett of the Australian Reptile Park, VICE added: “Queensland is actually home to the world’s largest captive crocodile, Cassius. Measuring in at around five and a half metres long, he’s estimated to be more than 110 years old. When I asked Billy what he thought of the proposition that saltwater crocodiles could not biologically die, he was skeptical. He did concede though that there’s not a lot of research around the aging process for crocodiles. In captivity, stress appears to stem their lifespan. In the wild, most crocodiles are relatively young because the market for handbags in the early 20th century wiped out anything older than 100 years.” – WTF fun facts

Source: “Old Crocodiles Never Die, They Just Keep Getting Bigger” — VICE

WTF Fun Fact 12803 – Real-Life Lassie

Has your dog ever done something so smart or seemingly compassionate that you’ve compared them to a real-life Lassie?

The Nevada County Search and Rescue certainly feels that way about a border collie named Saul.

Collie becomes real-life Lassie

In a July 14, 2022 Facebook post, the rescue team described what Saul did for his 53-year-old owner, who was on a hike earlier in the week in Nevada County, California.

On July 12, the duo set out for an adventure, but the man fell 70 feet down the side of a hill. Even worse, he was out of cellular service range at the time and could not call for help.

It wasn’t until the next day that the injured man – who broke his hip and ribs – managed to get himself to an area where his phone worked and call for help. CalFire immediately sent out the Search & Rescue unit, but it was Saul who found them first.

The big rescue

According to the FB post:

“Earlier today SAR was requested by CalFire to assist in searching for a 53 year old male that had fallen approximately 70 feet and complained of a broken hip and broken ribs. 25 SAR Members responded and located the subject but the true credit goes to the subjects k9 Border Collie that ran through the forest approximately 200 yards and in true ”LASSIE” fashion to flag down two searchers and led them back to the subject which was covered in a camo tarp.

Sar members packaged the subject and transported him to a landing zone a half mile away where CHP H 24 was standing by to transport the subject to a air ambulance a few miles away.

Great work and skill by all involved today and for the Border Collie he was transported back to Grass Valley and given a well-deserved dinner.”

“Like a movie”

Sergeant Dennis Haack of the Nevada County Sheriff’s Office Search and Rescue told CNN affiliate KCRA: “At first we didn’t believe it because it sounded like a movie. When they came back and actually described it to us, the reality was that they had followed the dog directly to the victim.”

Hiking accidents can be deadly since victims can be hard to pinpoint and locate in wooded areas or in places where satellite service is spotty. The rescuers received the call at noon, but it wasn’t until 7 pm that they managed to read the victim.

But once Saul heard them nearby, he knew what to do.

“(Saul) was jumping up and down and spinning around in circles,” Haack said, according to KCRA.

What a good boy!

– WTF fun facts

Source: “This dog led rescuers to his owner after he fell 70 feet on a hike” — CNN

WTF Fun Fact 12800 – Monkeys and Bananas Don’t Mix

Color us shocked by this one. We had no idea that monkeys don’t actually eat bananas in the wild OR that bananas are actually really bad for monkeys!

Monkeys love bananas, but…

Monkeys love bananas the same way we love junk food. And when people first started to keep monkeys as pets, they would give the creatures choices of things that grew locally. It turns out, that monkeys often chose bananas simply because they’re tasty.

If someone asked you what you’d like to eat and put down your favorite snack next to a bunch of vegetables, you’d probably reach for the sugary snack. Our brains love sugar. Unfortunately, for all of us primates, sugar isn’t good for us. It can affect our teeth, interfere with our digestion, make us gain weight, and lead to diseases such as diabetes and heart disease.

The same goes for monkeys.

Bananas are for humans

We think of bananas as healthy because they have a lot of potassium and our bodies are a lot bigger than a monkey’s. When we eat a banana, we taste the sugar, but it’s not really enough for it to be considered “junk food.”

The way bananas are grown, they simply don’t have enough protein or fiber for them to be of much nutritional use to monkeys.

According to Dr. Amy Plowman at Paignton Zoo in Devon (who made news when she banned bananas for monkeys) said: “People usually try to improve their diet by eating more fruit – but fruit that’s cultivated (grown) for humans is much higher in sugar and much lower in protein and fiber than most wild fruit because we like our fruit to be so sweet and juicy…Compared to the food they would eat in the wild, bananas are much more energy-dense – they have lots of calories – and contain much more sugar that’s bad for their teeth and can lead to diabetes and similar conditions.”

Of course, weaning monkeys off bananas is just as hard as telling humans to stop eating sugar. Monkeys should be eating leafy greens instead. Of course, a captive monkey can be stripped of the choice of what to eat, so improving their diet is a lot easier than improving our own. – WTF fun facts

Source: “Monkeys banned from eating bananas because they’re unhealthy” — BBC UK