Simplify the following text for a Grade 6 native English-speaking person.
Original: A litter box , sometimes called a sandbox , sand box , litter tray , litter pan , catbox , or cat box , is an indoor feces and urine disposal box for cats ( as well as rabbits , snakes and other pets that naturally or through training will make use of such a repository ) that are permitted free roam of a home but who can not or do not always go outside to relieve themselves .
Simplified: A litter box ( sometimes called a sand box , a litter tray or a litter pan ) is a place for cats and some other pets to use as a toilet .