These troughs are covered with a waxy water-repelling substance which has the effect of rolling the droplets down the beetle's inclined body and into its mouth.

So, if your child is inclined to rolling up her sleeves and building things, she'll enjoy putting together a cool robot and learn how to develop a simple program to test it out.

In this paper, the herpolhode and polhode os a rolling ball on an inclined plane have been obtained and discussed by analysing the motion of this ball.