Okay, first of all my hens, as far as I know, don't have fingers. So how does my heating lamp in their coop gradually keep getting unscrewed. Checked the lamp just yesterday after we had a few cool nights here, only to see that it was substantially unscrewed and hence, had not been working. I screw it in tight each time, so how does this happen? By the way I am using one of those radiant heater 'bulbs', the ones that just give off infrared heat and no light. Thanks in advance!