MEAN, MEAN MEAN!!! Even to each other. I have a pair of red eyes (t. lorteti). I had a male with 3 females. The largest female killed off the other two, until there was only the pair. She even bit ME! My lfs had 5 Targets (t. leiurus). The picked each other off, one by one, untill the last one was so weak, it died too. I have heard of folks breeding targets, so maybe they're better off in pairs, too. You can't sex them though (red eye sexes look totally different from each other). Also, the lfs had them all in a 10gal. I think you'd probably need about a 40gal w/lots of hiding places, for more than 1. As cute as my red eyes are, I really have to look for them most of the time, they hide a lot.