The tooth fairy don't nick

There's been a thief in our classroom. They took a bite of my sandwich and left muddy footprints and finger prints and crumbs everywhere.

The children are compiling a list of likely suspects. The potential criminals included:

The reception teacher
The whole of year four
The tooth fairy
The caretaker

But, as one of my children pointed out, it obviously couldn't be the tooth fairy. "The toothfairy don't nick."