Yes, and when they are swimming over a body of water, rattlesnakes actually hold their rattles up in the air. Over 50 years ago, I was fishing in a lake in central Florida and saw a snake swimming some distance away, holding its trail up above the surface. I rowed over to investigate, and it was a 4 and 1/2 foot rattler. I killed it with an oar, hooked it with a lure and drug it back to shore behind the board. I when skinned it, and cured the skin. My youngest daughter still has the skin today.
Eeeeewwww !!!!