You cannot, for example, leave most reptiles for more than a day. Even if the animal doesn't require daily feeding, the enclosures, water, and food should be regularly checked for feces and spoiling. Enclosures must be checked daily to make sure that the lights and heaters are working properly to maintain the necessary temperature gradients. Many reptile owners have gone away for the weekend only to return home to find their reptiles dead, bloated and decomposing from high ambient room air temperatures that unexpectedly increased the temperature inside of the enclosure. Others come home to find their reptile suffering from dehydration due to the lack of sufficient humidity, or with feces deposited in the rotting food or water bowls.
Lights burn out, leaving the reptile in the cold and dark.
Worse, some lizards and snakes are so adept at exploring their environments that their surprised owners come home to find their animal surrounded by shattered glass, fallen rocks or branches, or completely redecorated enclosures. Fires have been started by bored lizards looking for something to climb on and by cold lizards trying to get closer to their heat lamps. At home, you can provide all the heating and lighting necessary for the animal around the clock. At schools, all too often the heat or air conditioning is shut off at night and on weekends, leaving animals to freeze or overheat. When the teacher provides dedicated heating and lighting equipment for the enclosures, it may not be enough when the facility heating or cooling is shut off.