I realized while tying some flies that if you scrape some skins with your thumbnail, some type of clear liquid comes out. possibly water or some type of fat. It might be the way the skin was prepared. It also seems that this occurs with mostly bird pelts and un-tanned patches of skin from mammals. Currently I have no problems with bugs. Will it become a problem, or should I just forget it? Who else has this problem? Thanks for all the help.