it freaks me out sometimes, i'm scared he'll lean so far out he'll just tumble out.
i love them! after the inital setup they're pretty easy pets to have and they offer good desktop entertainment. i just worry insanely when they molt, and when they're stressed out they start dropping legs, which is kinda freaky.
if a crab trusts you, he will hang out like that and you can't get them to tuck back in even if you want them to.