I've had this happen several times. It doesn't seem to hurt the camera but I would get them out asap. I brought mine home and placed it in a plastic bag with a rag soaked with insect killer. It definately killed them off. I then opened the camera and cleaned all the dead ants out of it. I'm not sure what to do about keeping them out in the first place without causing too much scent on the camera.

Blessings.......Pastorjim