Appetite

Spiders do eat other spiders.

I’m sure I’ve read or heard that before, and I don’t suppose it should really come as much of a surprise to me. Still I was skeptical of this “fact” until today, in spite of knowing that some female spiders eat the males that come courting.

Cannibalism is not uncommon. Praying mantises eat their mates. Wild chimpanzees sometimes kill and eat other chimpanzees from rival social groups. Numerous animal species have been known to eat their own young. It may be rare, but humans do eat other humans on occasion.

I suppose it’s just surprising to actually see such a thing happen.

I was at my computer. I noticed a tiny spider (not much larger than the head of a pin) descending on a thread about two inches from the window frame. On the wall next to it was another spider that I recognized as the “jumping” variety (I have long been slightly unnerved by that type of spider because of their tendency to lean back, look at me, and sometimes even wave a leg or other appendage at me), which was two or three times the size of the other one. As the dangling spider slowly descended, the jumping spider would hop a little further down the wall. Suddenly, the jumping spider jumped (which should not have surprised me, considering the name of the creature, but it did anyway) away from the wall, caught the dangling spider, fell back to the wall thanks to an anchor line it had released as it jumped, and hopped a few more inches to the corner between the wall and the window frame.

Fascinating.

I did some research later and learned that this is perfectly normal behavior for jumping spiders. They are predators of other spiders and will typically drop an anchor before attacking. According to my research, they pose little or no threat to humans, and, if allowed to live in or near a house, can even significantly reduce the likelihood of more aggressive or dangerous spiders taking up residence.