The Tug-A-Jug is a treat dispensing dog toy that my dog Marta loves to play with. It has a narrow opening at one end (where only a few treats at a time can come out for a patient dog) and a screw-top lid on the other (which makes putting treats inside quick and easy for an impatient human). She usually can get a whole meal out of the Tug-A-Jug in about 7 or 8 minutes. But then Marta watched me put the treats in the lid side, and she decided it would be much more efficient for her to unscrew the lid, too. Turns out, you don't need opposable thumbs to do this!