Hello Huntinbull,
A "Decoy Heart" is a ball just like the one you are talking about. Mine is a little larger than a baseball. It has one AA battery and works the same as the one you described above. The web page showing a picture of it and the place to buy it is at this link: http://www.decoyheart.com/
I heard about it on a Primos "The Truth - Predator Hunting" Video. I guess it is also used in rubber goose, duck, and turkey decoys to make them move. The inventor uses it in the video for many of his hunts.
When I get my next cottontail rabbit, I think I'm going to skin it "case" style and put some light stuffing into it. Then I'll put the Decoy Heart inside to make it "irresistible". I'm just trying to get more ideas. Maybe I will try to find a styrofoam rabbit body, the kind that taxidermists use, then put the decoy heart in there.
