It's know as the "dissuasive effect", and it's well studied (see: https://www.sciencedirect.com/science/article/pii/B97801208894900 https://www.sciencedirect.c

It's know as the "dissuasive effect", and it's well studied (see: https://www.sciencedirect.com/science/article/pii/B97801208894900 https://www.sciencedirect.com/science/article/pii/B978012088...... and https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1744-1617.1990.015 https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1744-1617....... ) Now, obviously it isn't a magic barrier/tarp, but as long as there isn't too much of a cost/impact to making use of it, there is a selective advantage to taking advantage of this effect.