I wanted to buy a moon light but I dont know if it creates light for them
Incandescant lights are 5% efficient. Therefore 95% of the energy used is turned into heat. Flouresant lights are about 20% efficient. Therefore 80% of the energy used is turned into heat. LEDs can be as much as 40% efficient. So 60% of the energy is turned to heat. Moon lights are supposed to create light, simulating the light of the Moon. They're not terribly bright lights, so the total power used is low. The products i was able to find use LED lights. Chances are, the heat produced is minimal.
This got put in astronomy when Moon Light is apparently a brand of heat lamps, so this question needs to be put in Biology or pets.
You should post this in the pets section, not astronomy. Also mention whether you've got the kinds of hermit crabs that spend a lot of time out of the water, or not. When I was a kid I would catch hermit crabs from a nearby brackish lagoon and they were the type that doesn't leave the water. I had a salt water tank for them.
It simply reflects light.
