Had a couple of buddies come to the NM ranch for some coyote hunting.
We had an old adobe house that was at the headquarters everyone stayed in. Problem was, it was drafty, and rattlesnakes would come in frequently. I'd killed like 3 big rattlers in that house...
And I made sure to show them the pics. 
I knew none were in the house because I checked before they got there... but I did have an electronic caller that had "rattlesnake rattles" as a sound on it.
After supper, I put that caller under one of the beds the guys were staying in.
Waited for about 15 minutes after they turned out the lights and then used my remote control to turn on the caller already set to play the rattler sounds...
Things got pretty lively pretty quickly.
I let them holler for a minute or two, then went and turned the light on.... The guy that was sleeping on bed that had the caller was on a big table about 10 feet from the bed. I asked him how he got there?
He said he jumped. In the dark.... 
They were kinda relieved and kinda pissed when I reached under the bed and pulled my caller out... They could take a joke though.
