In the TV series *Growing Pains*, season 1, episode 6, there's the following conversation:

>Mom: Mike, don't forget that your father and I are going out... with the Koosmans tonight and you have to baby-sit Ben and Carol.
>
>Mike: Can't we get a sitter?
>
>Father: On this short notice, ***not one without an axe***.
>
>Mike: So? Ben and Carol are quick on their feet. 

   What's the meaning of "not one without an axe" here? What does this have to do with an *axe*?