Depends ... eg. kalo they go on autopilot (ikut the wired brains and noses) and are let loose without restraint and go chasing the pretty skirts for 2-3 days without much stopping for food and sleep (hey, they cannot help it ... their hormones are raging), they will. Tapi if they are confined in a cage or room or house and the only exercise they get is howling away (exercising only their jaws and diaphrams) while chomping on bowls of free flowing premium kibbles all day and night ... naaaahhhhh!!!