Dolphins
Dolphins are extremely smart mammals. They belong to the same family as toothed whales, which includes orcas and pilot whales. Found all over the world, most types of dolphins prefer shallow waters, but that varies from species to species. About five dolphin species reside in rivers. However, the remaining species live in other locations, determined by an assortment of factors like the availability of food, water temperature, and depth of water. Like habitat, diet also differs from species to species.
Dolphins' sleeping habits set them apart from other marine animals. They have to remain awake in order to breathe. Going into a deep slumber causes breathing problems. To overcome this challenge, half of a dolphin's brain is alert while it sleeps. This helps dolphins not only obtain the necessary amount of rest but also helps them stay alert enough to breathe normally. This ability is just one of the many outstanding qualities of dolphins.
To overcome this challenge, half of a dolphin's brain is alert while it sleeps. What does the word overcome mean?