I've tried the bathtub thing with some MM C brachycephaluses, once, and they all were able to climb out. ...I'm a little less scared of one of them climbing full bore up at me than I would be an H lividum, lol.
Haha, yeah! Especially since it was running around the EDGE of the container and not flat ground. That was a fun day. We had 20 cobalts to re-house.
dam that things fast