How to park digger

A blonde, a brunette, and a redhead are on the run from the law when
they find an old barn to hide out in. The police are close on their
tails, so when the women find three sacks, they immediately jump into
them. About a minute later, a policeman comes into the barn and sees
the suspicious-looking sacks. He kicks the first one.
"Meow," says the redhead.
"It must be a cat," thinks the policeman and he kicks the second sack.
"Woof," says the brunette.
"Must be a dog," thinks the policeman and he kicks the third sack.
"Potatoes," says the blonde.