This is a fairly common occurrence in the wild. As we know, antlers drop off deer every year. Once on the floor they are fair game for any number of critters to gnaw away on! Squirrels, mice and other rodents tend to use them to clean and sharpen their teeth, as well as an easy source of nutrients. Of these calcium and phosphorous are particularly abundant and desirable. Calcium is beneficial for bone and tooth strength and milk production, while phosphorous helps produce protein for growth and repair and also assists with proper organ function and energy storage. This is one of the reasons that antlers are so popular as dog chews (plus they tend to keep them occupied for a good while!) In addition to rodents I have also seen foxes and rabbits chewing antlers and in the highlands red deer are known to chew their own cast antlers to get the much needed minerals.