Like humans, animals can be left or right-sided. Sidedness refers to using one side of the body more than the other. Almost all vertebrate groups show signs of sidedness.
For example, humpback whales are usually right sided. We know this because researchers have observed that humpbacks have abrasions on one side of their body, but never on the other. This is because when humpback whales are looking for food, they dive and turn onto one side and scrape the mud on the ocean floor. The fact that abrasions are found only on one side of their bodies tells us that humpback whales always turn to the same side when diving.
Humpback whales are not the only animals that favor a certain side. Octopuses have a favorite tentacle that they use to handle objects with. Those who have a favorite tentacle also have a favorite eye that helps them focus on what they are trying to touch or grab.
While animals share the trait of sideness with humans, humans stand alone having the ability to be ambidextrous. Ambidextrous refers to the ability to use the left and right hand equally well. However, most humans are right handed and only a small number are ambidextrous.
[Source: Simpson Street Free Press Archives]