It's something a few of my roach species do on occasion, but particularly my skunk roaches/eurycotis floridana. I'm not sure if it's related to mating, releasing chemicals, or just a behavior that helps them to molt... but I find it rather cute. They will just sit in one place, and randomly... vibrate. Their segments start to swell, always in the same two spots, and then they just start shaking in bursts. Would love to know the reason why they do this!

I'm in the process of uploading a video of this strange behavior. It should be in the videos section in a couple of minutes.

You know, my hissers have been moving oddly lately. I think it's the beginning of them giving birth? it's only a prego female doing it. her whole hind end is really big, and open at the end. Has been for a few days. She seems to be "breathing" often too. Her hind end will wiggle left and right real fast a few times, then she goes back to "breathing". Dunno if it's related or anything, just thought I'd share/ask what she's doin.