If you frequently find poorly buried rawhides, bones or even toys in the backyard (or your couch cushions!), you're witnessing something called “caching,” a very common predatory behavior used by wild animals to hide food for later consumption. “Burying food and toys harkens back to dogs’ wolf origin. Wolves gorge on prey but may not be able to entirely consume it,” explains Dr. Stephanie Borns-Weil, DVM, clinical instructor at Cummings School of Veterinary Medicine at Tufts University's Animal Behavior Clinic. “They may cover it with earth to protect it from scavengers.”
Although not all modern dogs exhibit this behavior, it has persisted in many domestic dogs despite the fact that they rarely need to protect leftover food (or half-eaten bones) from predators in their living rooms, crates, or back yards, explains Borns-Weil.
While dogs' wild ancestors would eventually dig up the leftovers to eat them, this doesn't always happen with modern dogs. “One of our dogs was so persistent about hiding rather than chewing on his rawhides that he would even uproot our house plants in order to cache his fine chewables underground,” explains Trish McMillan Loehr, who holds a Master’s degree in Animal Behavior from the University of Exeter in England, and is a certified dog trainer and dog behavior consultant. “He never did go find them to chew later, either.”