I have two bettas in separate 8 liter tanks that sit next to each other. One morning while I was feeding the bettas, I, for some odd reason, opened both lids of the tanks and reached for the food. Obviously by now, the bettas recognize the red jar has food. So off in a frenzy they swim. As I move my fingers with the pellets in between my thumb and index towards the one on the right, (they probably planned this) both bettas jumped out of their tanks and into their neighbor's tank! So my black betta fell into my red betta's tank and vice versa. Shocked and really amazed, I just fed them. They are back in their correct tanks now.