Vexing the dog with PVC conduit

Sometimes I get lengths of PVC or aluminum conduit or dowels with my banners. One fun thing to do with them is annoy the dog. She can't figure out what to make of the noise coming out of the end of it. This strategy is handy when our puppy has the urge to bite everything in sight. At Home Depot they have rubber feet that fit on the end so if I make a stool or something I can likely find some feet to finish it at Home Depot.