I have deer chew on my lines quite a bit. They chew only on the drops and chew it like bubble gum. The whole drop will be chewed on but as bad as it looks it usually doesn't leak. As far as deer taking down the lines we hunt in our sugarbush and deer will come through the woods on a dead run and almost never touch a line. Go under over whatever. My nieces husband did shoot one one time and it took off running and did closeline itself but deer normally don't hurt the lines much here. Theron