Ants in my Desk

Ants, why are you in my desk? There is nothing for you here.

In my desk and supposed to be: computer mini-tower, little kid drawings, tin of oil pastels, language CDs, firmly sealed inkwell. In my desk mysteriously: ants.

Still have a head cold that makes everything bleary, but I think the ants are real.

Update: The ants are gone. Where did they go?