Cave

Caves were used as homes to the Cavman living in Wasteland. they were occationally homes to wild Dinos. Bob is somethimes seen living in a cave with his Alien tutor Martang, these episodes are set in older times of the Martang and Bob Series, in episodes set later in the series, they live in a house.

Behind the scenes
In some episodes Martang and Bob live in a house, and in episodes that are obviously set later in time, they live in a cave. Oops! maybe its a summer home. oh well, it doesn't really make much of an issue.