True story -- I found a mantis egg sack and knew it was a mantis egg sack, so I brought it into my library and put it in a jar on the information desk, hoping that it would hatch while I was there.
UNFORTUNATELY -- it seems that it hatched in the morning before anyone was there and when the first people arrived, there were tiny mantises crawling all over the information desk. (I forgot that they would be smaller than the air holes I had punched into the lid) oops. By the time I got to work, they had been swept up and were gone and yes, the rest of the staff screamed at me.
(most of my science experiments that I put out for the enjoyment of the customers backfired on me like that one.)