A couple of kids are looking at a poster for a flea circus and it centers on the strongman flea called Ferocius Flea. The ringmaster tells the kids that there will be no show today and shoos them away. He tells the fleas to take the day off and he and Ferocius plan to rob the banks around town. The ringmaster brings the flea in on his dog and the flea goes into the safe unnoticed with the briefcase and takes the money out of the safe and returns outside unnoticed. They rob several banks this way and the mayor of the city calls on Atom Ant to solve the crime spree.
Atom Ant shows up and finds clues that point to a flea being involved in the crimes. He checks the local flea circuses and finds Ferocius Flea. They begin to fight and Atom Ant wins and the flea and his ringmaster are arrested.