Effects of habitat on behavior?

[BugChick]

I'm sure I'm not the only one who's noticed that how you have your roaches set up impacts the kinds of behaviors you observe from your roaches. What have some of you seen?

For me, Blaberus spp. including discoidalis are adorable when you give them at least an inch of soil substrate. The nymphs swim around in the substrate, occasionally poking their antennae to check things out. Very cute!

I've also noticed that territorial behavior is seen if you have only a few roaches in a cage. When I say a few, I mean less than ten with only one or two males. The alpha male will develop bold behavior and stand sentry on the highest point of the cage. I even once had an African bullet roach charge towards my hand when I was doing cage maintenance. I've also seen this type of behavior with Archimandrita and hissers (obviously). Unfortunately, once the colony gets larger, this kind of behavior is lost.

Another thing with the smaller colonies is that there will be mysterious adult male deaths. It's as if the alpha male intimidates the lesser males from sharing in the resources (food, heat, water) until they die from the stresses of isolation.

[Nails]

I have also noticed this behavior with my large colony that they will sit on top of the egg crates as sentry's. Not as offense, but as defense to serve as an early warning for the rest of the colony.
I've also noticed that there would be a couple by the food dishes.
But at the same time I thought maybe it was b/c of the amount of roaches and they were waiting on a female to come out to molt.

Mike

[BugChick]

I think they stand sentry in order to dominate the territory, not to act as alarm signals. In other animals, not just roaches, males evolve to become bigger and stronger for the sake of dominating other males of the same species--not for protecting the colony as people would like to think. There's a whole niche of research dedicated to this specific kind of behavior and how it evolved.