Why do roaches go nuts a few nights out of the year?

In places thousands of miles apart I’ve observed that a few nights out of the year the large brown roaches go absolutely nuts outside. You’ll see them almost swarming, flying around in a hyper manner crawling up and down the walls of the house like a frenzy. Especially by the outdoor lights, which they usually are not attracted to.

Ditto for one or two inside, makes them easy to kill since they expose themselves and don’t seem afraid.

Mating season.

Also some animals (also plants) have a tendency to do mass group things once in a while. This way other things can’t grow dependent on them as a food source.

What plants do this?

A lot of plants, including oaks and bamboos, undergo mast seeding, synchronous production of seeds at long intervals in order to satiate seed-eaters.

I’ve heard that ingested poison (like those little plastic bait pucks you can get at the grocery store) also changes their behavior, making them less likely to hide or avoid light. I saw a roach behaving strangely as in the OP – just one, though, so it wasn’t a mass mating thing – and even though the damn thing hung out in broad daylight on the side of a brick wall for a couple of hours, not a single bird touched it, implying that birds either knew instinctively that the unusual behavior was a bad sign, or had learned that eating one anyway would taste bad/cause tummy aches.

Any truth to that theory?

I was reading today about urban bee keepers leading to more swarms in city centres. The reasons for swarming were said to be either mating, a Queen is born and the group are looking for a new home, or they’re living in a crowded environment (the beehive) and this causes them to swarm.

My thanks to the both of ye.

Have you done anything to rile them up ?

If it’s a mating thing I do hope not.

Makes sense…

BUT, do roaches HAVE a mating season?

I thought they were ALWAYS making baby roaches.

Rats have a swarm season every few years, where their population explodes. Turns out it is linked to the bamboo seeding cycle. All that new bamboo floods the rural woodlands, providing abundant food. The rats have plenty of food, and don’t exercise the habitual cannibalization that occurs when food sources are more typical. Ergo, a huge swathe of rats feeding in the woods runs out of bamboo, and then races into more populated areas like farms, devestating the crops and causing ruin.

My point is that these things are interrelated and you might not know the cause of it.

Cicadas are known for their 17 year cycle. Maybe beetles have their own cycles.

Or maybe it’s environmental, tied to flooding from the rainy season like we’re getting this year in the mid US. Texas and Oklahoma are flooding from the extended storms. Bugs don’t like drowning.

You are mostly correct (except queens aren’t born, they’re hatched), but this phenomena takes place in a hive where all the bees are already together, and can easily act as a group. Swarming is the natural way to reproduce a hive.

What the OP is asking is more akin to reproductive synchrony, where widely-dispersed organisms act independently, but their actions happen all at once. Corals and cicadas do this. I have no idea if cockroaches do; the OP may have been observing food-seeking behavior.

In Bangkok you often see a noticeable increase in roach activity at the start of the rainy season, when the homes they’ve made for themselves get flooded.