I found my cat drinking out of the tank one day.
I didn't have a very good cover, and he was able to push his head under it.
Now in my divided 10 gallon, the cover I have is plastic canvas (the same stuff I used for my dividers), and I came home yesterday (twice) to one side of the cover pushed in and the divider being all crooked. I don't know what he's doing. He's stepping in it or something (he likes to sit in the windowsill behind it).
He has noticed my fish but seems more interested in drinking out of the tank than catching the fish.
I need to get a piece of glass cut to size to put over the tank or something. I can't put a hood on it because of the light I use.