Published: August 19, 2013 3:00 a.m.
Cute break: Pocket mouse pups
Associated Press photosCAT
This photo provided by the San Diego Zoo shows two Pacific pocket mouse pups that ventured away from their mother outside their artificial burrow at the San Diego Zoo. The week-old offspring, which are less than an inch long and weigh just 1 gram each, are typically found with their mother and three other siblings nesting inside a 4-ounce baby food jar, but become more active at night. The jar and PVC pipe are designed to mimic the tunnels and burrows the Pacific pocket mice would dig in the wild. San Diego Zoo | Ken Bohn
These pups and their mother are part of a captive breeding program for this critically endangered species managed by staff at the San Diego Zoo Institute for Conservation Research in cooperation with the U.S. Fish and Wildlife Service. During this inaugural breeding season four females have given birth to a total of 12 offspring. San Diego Zoo | Ken Bohn