Everything about Prairie dogs points to them being complex animals, even their homes. They dig elaborate burrow systems underground, which connect as many as 6 entrance holes. The entrance tunnel goes down between 1 and 3 metres, and the rest of the burrow system stretches out for a further 3 - 5 metres, including a toilet chamber, and a nest chamber where they can sleep. They even create small side chambers so that should prairie dogs meet in the narrow tunnels they can use them as passing places. This system is remarkably sophisticated engineering, and it's deep in the safety of this burrow underground where the pups are born in spring. They are blind and without fur, so they huddle together for security.