Oh yeah, semi-aquatic newts, toads etc. are *the worst* for jumping...same thing for crayfish, crabs etc. and eel shaped fish. These need window screen, or something similar - and yes, definitely window screen is the best thing to use Some people prefer not to have anything evaporate, I have a friend like that who has a feeding hole the size of a dime and the rest of the tank is completely covered with a glass top cut exactly to fit the filters and equipment. I feel claustrophobic when I look at his tank for that reason (well, that and the fact that he has sooo much rock, decor and driftwood in it) but he likes how neat it looks (since nothing shifts around at all) and the fact that he almost never tops up for evaporation.