There were 3 robbers chasing 3 girls.
The redhead hides in a bush and the first robber asks the other 2 what that noise in the bush was.
The redhead then makes a sound like a snake (ssss).
The robbers say oh, it's only a snake.
The brunette hides in a tree and the second robber asks what that noise in the tree was.
The brunette makes a sound like an owl (hoo-hoo).
The robbers say oh, it's only an owl.
The blonde then runs into the barn and hides in a sack that says potato on it and the third robber asks what that noise in the sack was.
The blonde says potato!