is the cola completely missing? if so it mite be a deer or rabbit, and idk for sure if it comes of in the rain, i would guess yes, i think u apply it fairly often too, like every other day, i could be wrong so u may want a second opinion. and i wldnt worry about the chopper, start wrrying when they circle back and are hovering over ur shit, planes are nothing to wrry about either, my grow is about 200-300yrds from our local airport, i have planes over my head non stop, what worries me is when ppl go skydiving up there, first time i saw it i got real paranoid, but ive gotten used to it and realized that it all probably blends in when ur up that high, i think it being near an airport will deter choppers too bc flying in that zone would clog up the airspace and be very dangerous