ToyShoppe Playables Wire Ball Petsmart (store only, not online) - $1.99 RattyRat's Review: This cat toy makes a great treat ball for rats. Simply Bend two of the bars apart and take out the fuzzy ball from the inside. Then take a treat or too and wrap it up in some kleenex or paper towels and then shove it in the wire ball and bend the opening back shut. Rats will have lots of fun trying to get the treats back out. You can also choose large nuts that are too big to fall through the bars, or hunks of apple/pear. Use anything that is big enough to not fall through the bars, or if it's smaller treats, wrap them in kleenex/paper towels. Be sure to use plain white paper products with no added chemicals or perfumes.