Whales with teeth are classified as apex predators, and many of them prey on birds. Killer whales are one of the toothed whales that have been discovered feeding on birds. They are also known to devour big white sharks in addition to birds.

Whales eat krill, but not all of them. Nevertheless, these tiny shrimp-like invertebrates are abundant beneath the ocean’s surface and provide a significant portion of the nutrition for these massive creatures.

Whales with baleens but no teeth prefer to eat shrimp, krill, planktons, and other small sea creatures. Having said that, each whale species has its favorite food, and not all of them eat the same things.

Whales do have ears. But, even though they have external auditory canals, their functionality is questionable, just as it is in the case of all cetaceans. It is believed that whales have an especially designed sound system that helps them hear sound underwater. As such, they can easily hear sounds underwater and also communicate with ease.

Whales sleep for about 30 minutes at a stretch. Some whale species sleep for no more than 10 to 15 minutes at one go. This is because sleeping for longer durations will lower the body temperatures of whales, which can be detrimental to their being. Moreover, whales need to keep swimming to breathe or to escape predators.

Humpback whales are baleen whales that have a flat or horizontal whale. They could move their tail up and down to move underwater. We also know these whales for being one of the most acrobatic whales, and it is their tail that helps them breach the

Blue whales possess tails, which enable them to swim and control their movements underwater. A blue whale tail is straight and has a split at the end in two robbery lobes, known as flukes. Their tail assists blue whales in propelling their long and slender body underwater. 

Killer whales have more than one fin. In fact, they have four fins in total – two pectoral fins, a tail (or caudal fin), and the most important fin named the dorsal fin. Together, these fins help balance the whale in the water and allow it to keep moving forward. 

Dorsal fins assist fishes in rolling, taking turns, and stopping underwater. Dorsal fins are composed of connecting tissues devoid of any bone or cartilage. We can categorize dorsal fins into six types:
Single
Pointed
Split
Spine Triangular
Trigger
Trailing

Gray whales are migratory whales who also happen to be baleen creatures. Blue whales are baleen whales, but they are not considered migratory birds, although they move between summer and winter feeding grounds. Apart from their appearance, there are several differences between the two whale species. Needless to say, there are certain similarities as well.