Improper food causes diarrhea and death. Treat as an injured animal. Place papers or ravel free cloth in the bottom. Get and keep the body temperature warm using a heating pad under half the box so the animal may choose. A hot water bottle or jar or warm water wrapped in a ravel free cloth will also provide warmth.
Stress is the biggest killer, so keep the animal away from people and noise.
Darkness is safety to them. Keep away from TV or radios, keep your car radio off when transporting. It is not true that a wild mother animal will not take her babies back after they are touched by humans. Bats are the only flying mammals. There are no vampire bats in this area.