...a earth worm? He didn't like flakes so I gave him an earth worm. I saw him eat a little, should I just leave him with the worm to eat for later? he is about 3 inches. Should I take him back to the lake and set him free? I like him and think he is neat, but he seems sad, and wants to be with his fish friends, but my tank is only big enough for one. And also is there a type of plant I should get to put in the aquarium if I decide to hold on to him for a little longer.