Hey, i have a pet crayfish, i also have two fish living with the crayfish, i have a light built into the tank but i turn that off at night, i keep a flashlight facing the tank though so that the fish can escape or see if the crayfish is coming to attack them, i was just wondering thought if the light wold disturb the crayfish sleep pattern because i know he is noctornal and if he sees the light would he hide from it and try to sleep again? i was just wondering i i should turn the light off or not?