I can't say that Deer Whistles are a joke. I have an electronic one on my RSTD and it saved me from hitting a large bear near Revelstoke, BC last summer. He came running across the road and it's like he all of a sudden heard the hi pitched sound and bolted back to where he came from. I'm assuming it was the whistle he heard and not my bike. At any rate I missed him. It's also caused deer on 2 other instances to run back into the trees as I approached.