Why the hell would I be wondering “Can a tarantula bite itself?” As a chronic overthinker and someone who is susceptible to anxiety (I’ve talked about this before, ya’ll), sometimes thinking about all the different ways something could go wrong backfires. But I promise that for once, it was not ME who came up with this topic!

I started to wonder about this after I posted a meme on my tarantula Facebook page of a tarantula being adorable and pouting because it stepped on its own spider paw. It’s one of my favorite memes:

And one of the page’s fans (unfortunately I’d forgotten the name and didn’t save the old post) commented and stated that their own tarantula had bitten her own leg during a feeding AND DIED. After hearing that, I REALLY started to get those paranoid thoughts about my own Spidey biting herself!

If you’ve witnessed your hungry tarantula take down a roach, worm or cricket, you’ll notice that sometimes all you can see is a flurry of fur and legs moving before the kill is complete. Seriously, some spiders are FAST. And now that she’s gotten more of an appetite over the last few months, I have become deeply concerned after reading that comment on Facebook and have worried *every* single time Spidey eats that she is going to bite her leg during the chaos!

So can a tarantula bite itself?

Well, apparently yes considering a tarantula owner stated that it was a possibility and unfortunately, a fatal error :(. But the data besides that report was limited – when I googled this, I could barely find anything! Perhaps it’s because we expect tarantulas, due to their being around for so long, to have evolved instincts to the point that they don’t make silly mistakes like this. But apparently, it can happen. I did some googling and a pretty interesting arachnoboards thread came up about this (it was like THE ONLY thing that came up about this) and a user shared another instance (fortunately non fatal) in which a tarantula accidentally punctured itself:

Well, I once had an incident where my female P. Irminia slapped my paint brush and for some odd reason, her tarsus got stuck in the hairs of my brush, as I tried to free her leg she started biting the brush puncturing her tarsus with her fangs in the process. She leaked a few drops of haemolymph but the wound healed up and thankfully she didn’t decide to toss her leg. I was extremely worried that she might have injected venom and was scared it might be fatal, but she’s fine. So my guess would be that they are immune to their own venom. Just my guess though.

So it seems that yes, a tarantula CAN bite itself – but I think the question that we have to ask next is what determines fatality? Is it the venom or is it the puncture?

As you may know, a puncture to a tarantula can be fatal because their circulatory system is open and they do not have the blood clotting abilities that we do. That’s why every tarantula owner should know how to clot their spiders in case there is an injury. It’s possible that in the fatal instance I described above, the spider might have bled out or died from its venom. It’s hard to tell which one, or if it was both. In the second instance where the tarantula survived, it seems that the wound or venom was not enough.

Tarantulas are not immune to tarantula venom. If you know anything about tarantula mating, you’ll know that often times one of the tarantulas is lost due to a fight breaking out. Tarantulas are perfectly capable of consuming other tarantulas and it’s quite common practice for experienced tarantula owners to feed their weak, sick or dying tarantulas to their healthy ones as meals. They may even eat each other in the wild. Another complication to this is that a tarantula bite can either be wet or dry – a dry bite will not inject venom so this could be another factor in whether or not a tarantula bite to its own body is fatal. So are they immune to their own venom? This is where things get tricky and we need far more data.

Some snakes such as the cobra are known to be resistant to their own venom. And some snakes possess antibodies in their blood that protects them in case they happen to bite themselves by accident. A quora post yielded this response:

The mechanism of immunity to their own venom in cobras has been documented Dr. Zoltan Takacs several years ago. Most cobras kill by injecting (neurotoxic) venom that blocks nerve impulses to the muscles, causing respiratory failure. However, cobras have a large sugar molecule on their neuro receptors that blocks the toxin molecules from attaching to them, thus making them immune to their own venom if they accidentally bite themselves.

Most vipers, like rattlesnakes and Gaboon Vipers, do not have neurotoxic venom. Their venom is generally predominantly hemotoxic (affects the blood). So the mechanism of immunity is different; they have antibodies in their system that inactivate the toxins in their venom.

I guess the answer, for now, to the question “Can a tarantula bite itself?” is YES, but whether or not fatality is due to mechanical damage or the actual venom needs to be studied more. Do you have any thoughts or knowledge on this? Share it below!