A tale of two bugs.
As Aesop may possibly have told it.
This is the story of twin bugs, a story which could be repeated in many species but these two happen to be bugs.
To protect their integrity, we we’ll call them Walking Bug and Sitting Bug.
Being Identical twins they shared the same DNA and the same upbringing until they reached maturity and could make their own ways in life.
At this stage, they began to differ greatly.
Sitting bug spent every available moment resting and avoiding movement. He ate whatever he could find easily, whether it was good food or not, and he ate lots of it.
Walking Bug, however, walked whenever and wherever he could, He walked to find the healthiest food and because be enjoyed walking and liked discovering new places.
The future was easy to predict: Sitting Bug soon became very fat to the point where movement of any sort was impossible. He was simply too heavy for his legs. Unable to keep up with the local Lady Bugs he was rendered incapable of passing on his unhealthy ways to any offspring.
Meanwhile, his healthier slender brother proved very popular with the Lady Bugs and fathered many offspring to which he passed on his healthy way of life for many Bug Years.
OK, all very unlikely but you can probably think of another species where this is happening today. A reminder, if we need it, that inactivity is very bad for bugs and humans. Those who move more can help themselves to longer, fitter lives.