Alas, the original joke isn't mine. A textual form appeared in Phaic Tăn in The Jetlag Travel Guide Series, which is a parody of travel guides.
When I was in Vietnam, bargaining on the street was a bit like this. Without any common language, the vendor and I passed a calculator back and forth with offers and counteroffers.
Actually only the first two frames happened in Kandy, Sri Lanka.
Inspired by managing to fool seagulls into eating apple peel at Dee Why.
Another old joke. This was done in pencil for the course show-and-tell so to see a clearer version, click on the image.
I don't know if kangaroo repeller whistles actually exist, but deer repeller whistles do. The theory is that the ultrasonic tone from the whistle, which is mounted in front of the car, usually on the bumper, warns nearby deer to avoid a collision. Whether they work is debatable.
The other theme in the cartoon is the fantasy that reversing something simple, e.g. direction, polarity of battery, etc., can cause the reverse of a complex effect. I was reminded of this watching a Shaun the Sheep episode where Bitzer acquires a magical whistle that makes him master of the animals. Unfortunately he drops the whistle and reinserts the battery the wrong way around. The result was that actions got reversed. The farmer fixes the mess by grabbing the whistle and making Bitzer un-receive his whistle, restoring order to the world.
Anyway I'm also allowed to fantasise that one exists for humans. But repeller or attractor, or dual purpose? Ah, I'll leave that one ambiguous.
Another multi-frame cartoon. This actually almost happened to me. At a friend's house I playfully waved my finger in a circle in front of her Persian cat, intoning You are getting sleepy. The cat got annoyed at following my finger with his eyes and tried to swipe me.
The cloud in the third frame is meant to indicate general mayhem but also saved me from drawing details of the mauling.
I've thrown in some extra jokes, such as the author of the book.
I came up with this word joke upon seeing the words Pest Inspections on a van going past, and imagining the other meaning of inspection. I'm sure there is no such inspector, he'd go out of business pretty quickly.