they are caterpillars and they eat the nugs and they live inside the buds.if there is one there is more and they also eat like mother fuckers.i had some this year and last.if you see a brown leaf on one your your buds crack that nug open and you will probably see shit or a caterpillar.It is very hard to find them cause they are mostly inside the buds.Keep and eye out for them.Also your plants ant ready you have some time there is a thread on harvesting and curing were you could post a pic and he would tell you how much longer you have.And if worse comes to worse and you have to harvest early from the caterpillars then do so cause i got fucked before,i would see pieces of nugs missing and didnt know from what and they were from the caterpillars eating a way in the bud then they eat it inside out.Good luck..