How does an ant carry objects which are many folds heavier than its body weight

The observation of the feat of an ant carrying objects several times larger than its own body is a surprising fact. In some cases an ant is seen to lift objects even about 50 times its body weight. This makes us feel that ants are super strong because we can never even think of lifting a weight anywhere near fifty times our body weight.

When we lift an object, actually, we do not feel the weight of the object; we do rather feel the pressure which is the weight per unit area of application of the force or weight. For example, when we try to lift a bag of grocery by one finger it seems difficult, but when lifted by the full hand, it is not so hard because the same weight is now distributed over a larger area.

This idea can now be translated to the case of an ant or a human being lifting weights. When someone lifts an object, the weight of the object acts on the body and in turn is experienced as a pressure over the area on which he or it stands. In other words the weight is distributed over the area. An order of magnitude calculation would help us understand the act of an ant. A typical ant weighs about one or two milligrams, i.e. about 1000 or 500 of them would weigh one gram. Its six legs spread over an area of about 1mm square.

An object of 100 milligram weight, fifty times the body weight of an ant, would give rise to an overall pressure of about 100kg per metre squared.

On the other hand, a typical adult human being stands on an area of about 0.3metre squared on which his own weight of about 60 kg exerts a pressure twice as much as the ant does while carrying an object fifty times its body weight. And further, we do carry some more weight.

If we work back, for the same weight per square metre ratio as humans, the weight of an ant would be about 200 milligrams and it would have to lift 10 grams which it cannot. This observation of the surprising feat of an ant is, therefore, apparent, and not a real miraculous ability of an ant.

Yet another physiological reason appears to favour an ant over us humans. When we carry a weight, our muscles get deformed and the signal of the weight is sensed by the abundant nerve network present in the muscular tissue.

On the other hand the ant body is covered by a hard exoskeleton preventing local deformation on limited loading and inhibiting pain sensation. Instead, the weight gets transferred by the scaffolding of the exoskeleton on to the floor.