Whenever I see a tiny emaciated spider hanging on its web on the corners of the wall, I leave it alone. Perhaps it’s because I respect the life in it, but more importantly, I am in awe of its struggle for life. For 250 million years it has not significantly changed in shape and lifestyle. (Actually it should have been 300 million years, but spiders then had their “spinnerets placed underneath the middle of the abdomen, rather than at the end as in modern spiders”. Imagine lying down, facing the sky, hanging by a thread that comes out from your navel. Doesn’t seem like a very effective position to catch prey, does it? As such, these early spiders were thought to be ground dwellers.)
As much as I try to do no harm to spiders, I cannot say the same for ants. And I’m not only talking about those ants that march in the hundreds to attack our food, contaminating it with germs and parasites from whatever surfaces they had stepped on – including bathroom floors, garbage cans, and dog poop. I would kill even a single ant whenever I had the chance. Why? Because that single ant is a patroller on a reconnaissance mission, as explained by the National Geographic article Swarm Theory:
“When a forager has contact with a patroller, it’s a stimulus for the forager to go out,” Gordon says. “But the forager needs several contacts no more than ten seconds apart before it will go out.”
To see how this works, Gordon and her collaborator Michael Greene of the University of Colorado at Denver captured patroller ants as they left a nest one morning. After waiting half an hour, they simulated the ants’ return by dropping glass beads into the nest entrance at regular intervals—some coated with patroller scent, some with maintenance worker scent, some with no scent. Only the beads coated with patroller scent stimulated foragers to leave the nest. Their conclusion: Foragers use the rate of their encounters with patrollers to tell if it’s safe to go out. (If you bump into patrollers at the right rate, it’s time to go foraging. If not, better wait. It might be too windy, or there might be a hungry lizard waiting out there.) Once the ants start foraging and bringing back food, other ants join the effort, depending on the rate at which they encounter returning foragers.
So that single ant you did not kill will eventually bring in a whole battalion of foragers, which will contaminate your food with germs and parasites from whatever surfaces they had stepped on – including bathroom floors, garbage cans, and dog poop.
And so whenever I see an ant, I carefully pick it up so as not to squish it. Then I look for the nearest spider web and flick the pesky ant towards it. Bon appetit, poor little skinny spider! Eat well and grow. You’ll be handling cockroaches soon.