My store-bought chick has a hard thing on (I think) her fur. It is below the vent opening. Pretty sure it was there when we brought her home 4 days ago. Not sure if I should let it be (will it come off on its own?) or try to take it off. If I have to take it off, not sure what method might be best. I thought it was just a little dried poo from being in with all the other chicks at the store. It feels very hard like a twig.