Wikimedia Commons
Wikimedia Commons

Some Spiders Can Eat Bats

Wikimedia Commons
Wikimedia Commons

One night in 1941, G.C. Bhattacharya walked in to a cowshed in Calcutta, India and saw a small figure struggling and twisting against one of the walls. It was a small bat fighting its way out from in between two of the bamboo strips that the shed's walls were made of.

As he got closer, Bhattacharya saw that the crevice was not the only thing the bat was struggling with. A large spider was holding the bat by the neck with its mandibles and biting it. The bat gasped and screamed and struggled against its attacker, but the spider would not let go. When Bhattacharya lit a torch to help him see better, the bat shrieked and flapped its wings, freeing itself from the crevice, but not from the spider.

After managing to crawl along the wall a little bit, the bat exhausted itself and stopped moving for around 20 minutes before flapping one wing a few last times and stretching it out, as if reaching out to Bhattacharya for help.

The battle's victor clearly decided, Bhattacharya captured both the bat and the spider in a glass jar and brought them home for closer observation. The next morning, he found the spider resting upside down at the top of the jar, and the bat lying stiff on the bottom with visible injuries to its neck. It had not survived the night.

Bats’ most prominent predators are owls, hawks, and snakes, but a study published earlier this year reveals that spiders are also a formidable enemy, and that plenty of other people have witnessed incidents of chiropterophagy like the one Bhattacharya did.

To see just how common spider predation on bats was, Martin Nyffeler from the University of Basel (Switzerland) and Mirjam Knörnschild from the University of Ulm (Germany), combed through published research, blog posts and Flickr photographs and interviewed scientists who studied spiders and bats and veterinarians who worked at bat hospitals.

Altogether, they were able to gather 52 reports of bats being caught by spiders (whether in webs, or being actively hunted by non-web-building spiders), 29 of which had never been published before. Reports came in from every continent except Antarctica, but more than three-quarters of the cases happened in tropical areas around the Equator, most often in Latin America and Southeast Asia.

In most of these incidents, the spiders were large (10–15 cm legspan, ~1–7 g weight) web builders, mainly from the genus Nephila. These spiders are nocturnal hunters that spin webs up to 1.5 m across, and occasionally get together to build several webs connected to each other. The victims, meanwhile, were overwhelmingly small (10–24 cm wingspan, 3–8 g weight) insect-eaters, mostly from the family Vespertilionidae.

It doesn’t seem like the spiders intended to catch a bat every time. In some of these incidents, the spider completely ignored the bat caught in its web. Other times, the bat was known to be dead already before a spider found and began eating it. In these cases, it appears that bats simply sometimes get stuck in spiderwebs and die of exposure or starvation without being preyed upon, and sometimes spiders simply scavenge the body of dead bats without having killed them. In many cases, though, it was clear that spiders were intentionally killing and eating bats, immobilizing ones that got caught in their webs with a silk wrap, biting them and later consuming them.

Fifty-two spider-on-bat battles doesn’t not seem like a whole lot, especially when you consider that these reports cover a timespan of 100+ years. Indeed, Nyffeler and Knörnschild were actually surprised that that was all they found, given the sheer number of spiderwebs that must stand in the way of bats’ flight paths throughout the tropical parts of the world. They suggest that bats may be very good at avoiding spiderwebs with the help of echolocation. While the silk threads that make up the web are likely too thin to echolocate, the denser decorations and barriers that spiders place on them—plus the spider itself sitting in the center of web—should be large enough for the bats to detect in flight.

13 Facts About Opossums

Opossums, which include the roughly 100 species in the order Didelphimorphia, are some of the most misunderstood animals in the Americas. They’re often thought of as dimwitted, dirty creatures whose most impressive trick is acting like roadkill. The truth is just the opposite: Opossums are smarter, cleaner, and more beneficial to humans than many of their woodland neighbors. Read on for more opossum facts.


In North America, opossum and possum describe the same thing, but in Australia the word possum refers to a completely different animal. Among the most well known of their respective types are the Virginia opossum and the brushtail possum. Both are small to medium sized, omnivorous marsupials, but the similarities end there. The possum looks like a cute cross between a squirrel and a chinchilla and it belongs to a different order than the North American mammal that shares (most of) its name. Despite the potential for confusion, possum is accepted as the shortened version of opossum in this part of the world (and if you see the word possum in this list, you can assume it’s referring to the animal from the Americas).


Marsupials—mammals that carry and nurse their young in pouches—are absent from much of the world, and in Canada and the United States opossums are the sole representatives of the group. Like other marsupials, mother possums give birth to tiny, underdeveloped offspring (called joeys) that immediately crawl into a pouch where they live and nurse during their first months of life. Only once they’ve grown big and strong enough do they venture out, transitioning between their mother’s back and the warmth of the pouch until they mature into adults.


Possum playing dead.

Perhaps the most famous characteristic of the opossum is its tendency to play dead in front of predators. When the animal experiences intense fear in the face of danger, it seizes up and flops to the ground where it can remain for hours staring blankly ahead and sticking out its tongue. It’s an impressive defensive mechanism, but its effectiveness can’t be chalked up to the possum’s acting skills. Possums have no control over when they play dead or for how long they do it: The comatose-like state is an involuntary reaction triggered by stress.


A picture of a possum playing dead doesn’t really do it justice. To get the full experience, you need to be standing over to it to smell the putrid odor it emits when pretending to be a corpse. The smelly substance it secretes from its anus is just one more reason for foxes and bobcats to look for their dinner elsewhere.


Even if possums aren’t the cutest creatures in the forest, they should be a welcome addition to your backyard. Unlike other mammals that carry ticks, and therefore spread Lyme Disease, possums gobble up 90 percent of the ticks that attach to them. According to the National Wildlife Federation, a single possum consumes 5000 of the parasites per tick season. That means the more possums that are in your area, the fewer ticks you’ll encounter.


Possum looking up at table.

Opossums have impressive memories—at least when it comes to food. Researchers found that possums are better at remembering which runway led to a tasty treat than rats, cats, dogs, and pigs. They can also recall the smell of toxic substances up to a year after trying them.


While most animals look at a snake and see danger, a possum sees its next meal. The animals are immune to the venom of nearly every type of snake found in their native range, the one exception being the coral snake. Possums take advantage of this adaptation by chowing down on snakes on a regular basis.

Researchers have been trying to harvest possums’ antivenom powers for decades. A few years ago, a team of scientists made progress on this front when they recreated a peptide found in possums and and found that mice given the peptide and rattlesnake venom were successfully protected from the venom’s harmful effects.


While possums aren’t totally immune to rabies (a few cases have been documented), finding a specimen with the disease is extremely unlikely. Marsupials like possums have a lower body temperature than the placental mammals that dominate North America—in other words, their bodies don’t provide a suitable environment for the virus.


Baby opossum hanging from a tree branch by its tail.

Opossums are one of a handful of animals with prehensile tails. These appendages are sometimes used as an extra arm: They can carry grass and leaves for building nests or grip the sides of trees to provide extra stability while climbing. Baby possums can even use their tails to hang from branches upside down as they’re often depicted doing in cartoons. But it’s a myth that possums sleep this way: Their tails are only strong enough to hold them for a short amount of time.


Thanks to their whole acting-and-smelling-like-a-corpse routine, opossums aren’t known as the most sanitary animals in nature. But they take cleanliness seriously: The Washington Department of Fish and Wildlife writes that possums, like housecats, use their tongue and paws to groom themselves frequently and thoroughly. Possums largely lack sweat glands, and this behavior is believed to help them cool down. It also has the added effect of rendering them odorless (when they’re not secreting stinky predator-repellant, that is).


Close-up on opossum's face.

One of the opossum’s most recognizable features is its pair of opaque eyes. Opossum eyes do have whites and irises, but because their pupils are so large, their eyes appear completely black from a distance. The exaggerated pupil dilation is thought to help the nocturnal animals see after the sun goes down.


It was long assumed that opossums like to keep to themselves, but a study published in the journal Biology Letters suggests they have a social side. Researchers at the Federal University of Pernambuco in Recife, Brazil observed some possums in captivity sharing dens even if they weren’t mates. In one case, 13 white-eared opossums of various age groups were cohabiting the same space. The scientists suspect that male and female possums living in the wild may even build nests together as a way to trigger the female’s reproductive hormones.


The way it gives birth and raises its young isn’t the only thing that’s interesting about the opossum's reproductive life. Females have two vaginal tracts and two uteri, and males in turn have a forked or bifurcated penis. This is fairly typical for marsupials, but when European colonizers first landed in North America centuries ago, they didn’t know what to make of the confusing genitalia. One explanation they came up with was that male opossums impregnated females through the nose.

Hero Crayfish Cheats Death By Removing Its Own Claw to Escape Pot of Boiling Water

There remains a perpetual debate over the ethical consequences of taking a crustacean and boiling it alive. In early 2018, Switzerland actually made it illegal to give living lobsters a scalding hot bath. (Instead, chefs are expected to stun them electronically before submersion.) Scientists can’t reach a conclusion over whether decapods feel pain—or if we can even define what that means for them.

While humans argue, some clawed sacrifices are taking action. A crayfish filmed by a Facebook user in China is making the internet rounds and being hailed as a hero after taking dramatic measures to escape a boiling pot of water.

In the footage, the crayfish appears to be unable to extricate its left appendage from a bubbling vat of doom. Rather than succumb, the crayfish uses its right claw to sever its compromised claw and scurry off. At 11 seconds, it’s the best summary of a Saw film possible.

“Juike,” the user who originally posted the video to the Weibo social media site, says he has taken the crafty invertebrate home and put him in an aquarium as a pet. The tiny survivalist may even regrow his lost limb, as crawfish are able to do, although it might not reach its former size.

Crayfish are in inherent danger of being turned into soup in China, where specialty restaurants devoted to their preparation are popping up. Some observers believe their popularity is due to diners having to step away from phones and social media in order to use both hands to peel away at their shells.

[h/t BBC]


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