That has improved slightly, but it is still risky and injuries are still common. STO can be grumpy if disturbed in their nest while sleeping. Many owners can convince their STO to use a litterbox in a corner of the cage which can help make odor control easy. The tail, only being furred at the base, is almost as long as its body. a Center for Neuroscience, University of California, Davis, 1544 Newton Court, Davis, CA 95618, United States b Department of Psychology, University of California, Davis, 1544 Newton Court, Davis, CA 95618, United States Abstract—The gray short-tailed opossum (Monodelphis domestica) is a nocturnal South American marsupial that In those cases, owners can wake up to a dead or injured pet. The vet wasn't an exotic specialist. Some … One issue that is important to know is the majority of short tail opossums (even the ones that use a litterbox) also go to the bathroom while running in their exercise wheel. These extra bones migrated from the “reptile” jaw to the mammal middle ear over the course of evolution. Thalidomide was prescribed to pregnant women in the 1950s and 60s. Our findings suggest that opossums make a good mammalian model for future studies of the impact of thalidomide on human development. Much more difficult to spot because of its size and relatively small geography, the gray short-tailed opossum is known to be more aggressive than other species, especially while they are mating. google_color_bg = "F8E8B8"; We study how development has evolved to generate this diversity, using opossums, bats, pigs, mice, and horses. The possession of a middle ear with several bones is a key mammalian trait. Monodelphis brachyura.