Can't figure out why my pet toads keep dying, Please Help!!

[Motocrash]

Oh, I forgot to add.... When I do add a light, it's always a low wattage incandescent. And.... I rarely put more than one in an enclosure. When I do, it's usually just males. Males seem to pester the females when they are in the same box. I've never seen the males actually pursuing them, the females just seemed less enthusiastic when there were males around.