Call um crawdads or crayfish, either way there were a few big ones at some point. It could be why there are no fish. I was told that the crawdads eat the fish eggs by someone at some point.

The old tank is full. I watched for fish, but one ccalf wanted to play and I was partially afraid. For good reason when the rest of the came over also. At that point I halled ass out of there. I did not see any fish.