Like the one's they use in the high school "over the weekend - homework baby" sensor? That is such a cool idea. I don't know what you could do about them being dropped though.... I'll go check it out.You can Fry them when they are little. It might take a couple but do save the bones to make chicken broth from them.
Have you heard of drop sensors placed of packages? The Shipping experiment thread had a post about them.