When i have dolphins in a giant tank of water, they all gather into a corner and constantly jumps up and down from the water, like they are trying to escape the body of water. there are no items around for them to grab, nor any mobs for them to get scared by. i tried putting them in another giant body of water and the same thing happens.

once placed they behave normally, but then after a while they all swim to the same corner or edge and try to "escape."