Yes I must be crazy putting a crayfish into my angel fish tank where I have a school of corydoras and two common pleco. I added him in when he was still a juvenile with tiny claws. Out of the six or seven I had only 3 remain. My dad took the others for bait. He was one of the 3. He has molted 3 times since I added him into the tank. His front claws are large enough to catch a Cory if he really wanted to. But does he? Nope. He makes no attempt to hunt them or sit and wait for one to swim buy. I have watched him very closely since I put him in. There were many times where a Cory had swam up and just settled right in front of his claws or directly under him. Each time he would simply move along and search for the wafers I dropped in or that yummy shrimp pellet that was undetected by his tank mates. I feed him in and outside of the tank 3 times a day. The key is to keep him well fed. If he isn't hungry he won't feel the need to prey on his tank mates. I've even observed the corys and plecos of any visible signs of the crayfish attempting to catch them. I can confidently say not a single scar or missing fins or wounds can be found. All fish remain intact. I have heard horror stories of crayfish preying in their tank mates and I know it's something they naturally do. This fella even leaves the snails alone while the other two that I have in my room are always trying to eat the snails. Those guys I feed once a day so I'm sure if I put them in the angels tank I would have corys missing. I wouldn't leave the crayfish in there if I wasn't certain he wouldn't harm any of the fish. He's had about 3-4 weeks to eat any of the fishes in there but hasn't so much as lifted a claw at them. I will post another video when he molts again.