Looks like an ant, walks like an ant, but ... it's a spider?

July 18, 2017 7:23 AM

Imagine you're a tiny spider, just trying to make it in a big world, a world where you're likely to be eaten. Oh hey, ants seem to do well, you notice. I'll pretend to be an ant! Apparently the tactic is so successful that there are a few types of ant mimic spiders, including some members of Castianeira sp., and more notably the jumping spider Myrmarachne formicaria, which moves like an ant, even waiving its front-most pair of legs like antenna (full paper). Look closely in your neighborhood or local park, and you might even find a new species of spider that mimics ants.
posted by filthy light thief (16 comments total)

Spiders aren't the only animals that practice myrmecomorphy. Mantises do it too. And so do stick insects.
posted by pipeski at 7:32 AM on July 18, 2017

Spider-Ant, Spider-Ant ,
Spot the mimic? Sure they can't
Waves its legs, like antennae
Varieties, turns out there's many
posted by Gelatin at 8:01 AM on July 18, 2017 [19 favorites]

This is awesome. Even knowing what I'm looking at, I still need to pay really close attention to the head shape to figure out that it's not actually an ant.
posted by tobascodagama at 8:43 AM on July 18, 2017 [1 favorite]

I'm not sure I understand how this helps them avoid predators. Wouldn't they just appear to be a tasty ant snack instead of a tasty spider snack?
posted by Vectorcon Systems at 9:26 AM on July 18, 2017

Lots of animals avoid eating ants because of their chemical warfare, e.g. formic acid.

There is lots of mimicry happening in the insect world.
posted by Bee'sWing at 9:31 AM on July 18, 2017 [2 favorites]

Maybe I'm more of a silhouette person than a color person? But those just all look like neat spiders to me.

BUT I'm not a tiny spider hunting animal, so maybe this is working great. Not my place to judge you ms spider. You do you.
posted by French Fry at 10:12 AM on July 18, 2017 [2 favorites]

I approve of Cody Raiza's #spidertwitter!
posted by tavella at 10:56 AM on July 18, 2017 [1 favorite]

The spiders look like ants to avoid getting eaten by ants. Some also live undetected in the ant hills, picking off unsuspecting ants like Gollum does to Misty Mountains goblins in the Hobbit.
posted by cardboard at 10:57 AM on July 18, 2017 [8 favorites]

The spiders look like ants to avoid getting eaten by ants.

And bigger spider-eating spiders. Life as a tiny spider is not easy.
posted by filthy light thief at 11:06 AM on July 18, 2017 [4 favorites]

Yay nature!


But, let's be honest - this isn't going to prevent the swift judgement that's carried out in our house at the sight of any non-furry, non-domesticated, multi-legged creature.
posted by ovenmitt at 12:59 PM on July 18, 2017 [1 favorite]

I realize this is tangential, but when I read the description, I was stopped by the overwhelming reaction that spiders SHOULD NOT JUMP. EVER.
posted by pangolin party at 1:05 PM on July 18, 2017

pangolin party: I realize this is tangential, but when I read the description, I was stopped by the overwhelming reaction that spiders SHOULD NOT JUMP. EVER.

Johnny and I disagree. Really, tiny jumping spiders are the cutest! I loved finding them in my yard in California - they're (mostly) way too small to be threatening to people, and their jumping seems to defy physics.

Then again, I'm my house's advocate for gently removing all crawling critters who wander into our home and escorting them out into our yard.
posted by filthy light thief at 1:30 PM on July 18, 2017 [6 favorites]

I got a teeny jumping spider that normally hangs out on my desk lamp to chase my mouse arrow about on the laptop screen this morning. It was quite entertaining.
posted by Bee'sWing at 1:39 PM on July 18, 2017 [6 favorites]

I ♥️ Jumping Spiders
posted by Johnny Wallflower at 3:48 PM on July 18, 2017 [4 favorites]

*adds filthy light thief to the Wallflower Wall of Righteous Humans*
posted by Johnny Wallflower at 3:52 PM on July 18, 2017

I'm completely charmed by the mental image of a spider waving it's front two legs around to mimic an ant like cosplay
posted by bleep at 11:57 PM on July 18, 2017 [2 favorites]