How old do you have to be to work at...?

I want to know how old you have to be to work at the following:

Petsmart

Pizza Hut

Fazolis

Target

menardsHow old do you have to be to work at...?
14 and 9 mths I think

But they accept people who are younger sometimesHow old do you have to be to work at...?
i think you have to be 16 to be legally working