Several researchers are working to understand the role of mouse chemical communication in determining their characteristics. Researchers learn to eavesdrop on mouse communication that enables them to leave these rodents chemical messages that deter the animals from eating valuable provisions. It may also be possible to use the chemical signaling to control mice in places such as New Zealand, where indigenous bird populations evolved without rodent predators and are jeopardized because mice that arrived with British colonists are devouring eggs of endangered species. Robert J. Beynon, a protein chemist at the University of Liverpool and Jane Hurst, a behavioral ecologist, discovered that wild mice excrete some 12 to 15 different kinds of major urinary proteins (MUP) in their pee, all of which seem to adopt a similar three-dimensional barrel-shaped structure. The MUP protein barrel contains a cavity that can harbor volatile chemical signals.