Flea larvae actually prefer humid, shady spots, not standing water. So wet ground or leaf litter can help them survive, but deep or pooled water likely drowns them
I read that fleas are attracted to warmth and light more than anything else, set up a warm lamp and a water dish, and they hop right in. The water just slows them down and traps them
Fleas don’t like getting wet—water can kill them. But damp, moist areas can support their development and attract hosts, which means more fleas in your vicinity