wjones,
I too have a fondness for snakes. They are beneficial in the balance of nature for controlling mice and other vermin. However, I love my Martins more, and will do whatever it takes to deter snakes and to protect my birds. I have never caught a snake in my netting, but if I did, I would remove it and relocate it across the River to my workplace, which is out in the middle of nowhere (shooting range). I'm not sure how I would handle catching a snake inside the housing, especially after he had made a dinner out of my baby birds. Probably would not be a good ending for the snake. Once it learned of the easy meal in the PM houses, it would be very difficult to keep it away. Fortunately I have not faced that situation.
Bird netting is effective in stopping the snakes. Those that use it should check it every season for dry rot when putting their housing up at the beginning of the season. The sun tends to degrade the netting, and it needs to be replaced (eventually).
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