Our Pets Play-N-Treat Cat Toy Two Pack Petco (store only, not online) - $2.99 RattyRat's Review: These are the cheapest treat dispensing balls we've found. They pry in half to put treats into. rats can have tons of fun rolling them around to get any variety of treats out. Unfortunately they are somewhat easy for rats to figure out how to pry apart. Once this happens your rat will just start carrying them off and prying them open instead of rolling them around like they're suppose to. But for the inexpensive price, it is worth the fun they provide.