Then I'll bite 'em

"Benjamin! Don't suck on your toes!"
"Then, I'll bite 'em" Which he said happily, and started to do.


The rest of the conversation was pretty amusing, too:
Don't bite your toes.
Then I'll bite my fingers.
Don't bite your fingers.
Then I'll bite myself - arg (bites his arm) See! I bite myself (which he happily shows to his mother)

As you can see, he has done this before.

-Dom