I leave dry cat food out on the back deck for a stray cat that lives in my shed. Lately after about a half hour dozens of small ants descend on the bowl (plastic bowl, wooden deck). I've seen pet food bowls advertised that claim to be ant-proof. Some use a moat of water around the bowl which deters the ants. Hoping someone can recommend either an ant-proof bowl I can buy or maybe someone has a DIY idea for keeping the ants at bay. Thanks!