We have a little crab in our tank, and he's starting to get bigger, and seemingly, more aggressive. He doesn't both our fish much, but we often find him pestering the hermit crabs. We may think he's actually killing the hermit crabs--the reason we think this is we don't see as many hermit crabs crawling around like we used to, and there are several empty shells here and there we thought had crabs in them once. Plus, sometimes the water gets to smelling really fishy.
Please click this link to see a 10-second video of our little crab. He has about an inch-long body, and inch-long front claws.
So...is this crab a killer?