Watch ants closely for any length of time, and you'll witness some remarkable feats of strength. Tiny ants marching in lines can haul food, grains of sand, and even small pebbles that are many times their own size back to their colonies. And this is no illusion-studies show that ants can lift objects that weigh as much as 50 times their own body weight.
How can this be?
The answer to why ants-or any insect for that matter-are so strong lies in its diminutive size. It is physics, plain and simple.
The Physics of Body Strength
To understand the enormous physical strength of an ant, you need to first understand a few basic physical principles of how size, mass, and strength are related:
- The strength of a muscle is proportional to the surface area of its cross-section.
- Surface area, therefore, is a two-dimensional measurement, and it is measured according to the square of its length.
- An animal's size and mass, on the other hand, is determined by volume. Volume is a three-dimensional measurement and is calculated by multiplying three dimensions.
The key here is to recognize that an animal's weight is related to its volume, which is a three-dimensional measurement arrived at by calculating a cubic measurement. But the strength of a muscle, on the other hand, is a two-dimensional measurement, arrived at by multiplying only two numbers, length by width. The discrepancy here is what creates the difference in relative strength between large and small animals.
In larger animals, the much greater volume and mass mean that muscle strength must be far greater to maintain the same level of strength relative to body weight. In larger animals, muscles also have the added burden of moving the larger body volume and mass along with whatever object is being lifted.
A tiny ant or other insect has a strength advantage because of the larger ratio of surface area to volume and mass. An ant's muscles have a fairly small load required to lift its own body, leaving plenty of muscle power to move other objects.
Adding to this is the fact that an insect's body is inherently lightweight relative to its volume when compared to other animals. Structurally, insects do not have internal skeletons as do vertebrate animals, but instead, have a hard exoskeleton shell. Without the weight of internal bones, the insect's weight can comprise a higher amount of muscle.
The Ant Is Not the Weightlifting Champion
Ants are the insects we most commonly observe lifting heavy objects, but they are far from the strongest members of the insect world. The dung beetle (Onthophagus taurus) is known to lift weights up to 1,141 times its own body weight-a load equivalent to a human lifting about 180,000 pounds.