"tor"

A teacher asks the class to name things that end with 'tor' that eat things.
The first little boy says, "Alligator."
"Very good, that's a big word."
The second boy says, "Predator."
"Yes, that's another big word. Well done."
The third boy says, "Vibrator, Miss."
After nearly falling off her chair, she says, "That is a big word, but it doesn't eat anything."
"Well my sister has one and she says it eats batteries like there's no tomorrow!