In towns frequented by bears, it’s not unusual to see trash cans designed so hungry bears can’t get in. Some people strap down their garbage to keep out scavenging raccoons (Procyon lotor). In Sydney, the nuisance is clever cockatoos, which have figured out how to open garbage bins and peck for food, reports Science News. Residents have resorted to an arsenal of defensive measures to keep out the sulphur-crested cockatoos (Cacatua galerita). They’ve tried to weigh down lids with bricks and reinforce them with sticks. The cockatoos, in turn, learn how to get past the defenses. The result, researchers say, may be “an innovation arms race.”

“The socially-learnt behaviour of opening and raiding of household bins by cockatoos is met with increasingly effective and socially-learnt bin-protection measures by human residents,” researchers wrote in a study published in Current Biology.

Watch the cockatoos at work below.