If you have a very low deer population the fish line thing might work 10%. I will tell you this we have medium/high deer density here in cental Illinois and the only thing that will keep them out 99% of the time is an E fence.... With the crop production so screwed up they are looking for food and a piece of fish line wont stop them.The chemical thing has to be resprayed every few days to work half the time..I know people that have tried it all...