A question or two about swarming ants

Factual Questions
1

Today was ant swarm day in my neighborhood. During the course of my morning run, I saw dozens of nests which were turning out all occupants to send off the winged ants. It was actually kind of cool, seeing the fliers floating upwards with their wings shimmering like silver.

My questions:

  1. Why does the whole nest have to turn out? It’s not like they’re intelligent enough to stage some sort of bon voyage party!

  2. It certainly looked like the winged ants were being dragged forth from the nest by the workers. Is this the case? I always thought they’d be raring to go on their nuptial flights.

Thanks for any insights.

2

It’s been a while since I’ve read Wilson’s Ants, but I have a couple of marginally-informed guesses.

  1. Ants (and many other hive-type insects) communicate chemically. When an ant is running around, it’s leaving a chemical trail behind itself. This permits it to find its way back to the nest. If it finds a good source of food, it grabs a bit and follows its own trail home; further, it changes the chemical signature it’s leaving so when it arrives, the other ants will recognize the signature as “follow me to food.” This is how ant columns form. So if an ant happens to produce an “activity alert!” chemical, something high priority, it’ll get picked up on by every ant that passes and perceives that laid-down chemical, and each ant will then continue producing that chemical, creating a cascade effect that impacts most or all of the nest.

  2. Maybe the wings weren’t dry. The interior of ant nests can be pretty humid places, particularly on the micro scale of an insect, so it seems reasonable that the male, after hatching, would need to be brought out into the open air and left there for a few minutes before its wings would be functional.

Again, both of these are guesses, based on general information half-remembered from prior reading, and I expect to be refined and/or corrected by the board’s experts.

P.S. It would be helpful to know what kind of ants they are. Any identifying information you can provide will be useful.

3

Winged termites swarm, too.

4

Cervaise, I don’t know what kind of ants they are - basic, smallish black suburban ants of some kind. I live in the bay area of California.

I’ve thought about it a bit - I know that ants follow chemical signals, but I was wondering to what purpose the whole colony would turn out. I’ll bet it’s a safety in numbers kind of thing. If just the winged ants came out alone, they’d be pretty vulnerable and be picked off by predators. With several thousand workers surrounding them, they’re sort of lost in the mob.

And predators were out this morning, too. I saw pairs of scrub jays hopping about excitedly everywhere, picking flying ants off of grass stalks and snatching them right out of the air.