"Food puzzles were originally created to provide enrichment for captive zoo and laboratory animals. They typically consist of any object that can hold food and be manipulated to release food when the animal interacts with it. Food puzzles may be mobile (rolled or pushed) or stationary, and they can be used to provide either wet or dry food. They may be purchased or homemade."

"Benefits we have observed include weight loss, decreased aggression toward humans and other cats, reduced anxiety and fear, cessation of attention-seeking behaviors and resolution of litter box avoidance."

Reference:
Dantas LM, Delgado MM, Johnson I, Buffington CT. Food puzzles for cats: Feeding for physical and emotional wellbeing. Journal of Feline Medicine and Surgery. 2016;18(9):723-732. doi:10.1177/1098612X16643753