skeptic
A Faraday cage for hunting, huh? Count me as a skeptic. Sounds like snake oil, pun intended. Sharks are one example of animals that can detect small changes in the electric field caused by other animals muscle movement, but they live in salt water (very conductive). HowStuffWorks "What is electroreception, and how do sharks use it?"
Air does not conduct electricity very well.
The only other radiation (besides very small amounts of radioactive decay Radiation from humans) is thermal radiation, or infrared. Only snakes, I think, can see IR: Night Vision in Animals | dmohankumar.com.
JMO