I did this once when I was a kid. Saw a bug, grabbed my hunter cat and hoisted him up, expecting him to swat at it. Oh he smashed it, and then brought it to his mouth and started chomping. I had no idea to expect this and was so grossed out that I dropped him (sorry kitty — he was totally fine, if a little disgruntled).
Now my cats are pampered princesses with no huntress instinct whatsoever so I’ve resorted to a fly swatter.
To be fair, if I saw a driver shouting out their window at a bicyclist, I’d also think they were insane (and a monumental asshole).