Here's why they are classified as predators:
* They hunt and kill their prey: Blue whales actively seek out and consume krill, which is a necessary part of their diet.
* They have adaptations for hunting: Their baleen plates act as filters to strain krill from the water, and they have powerful tails for swimming and creating currents to concentrate krill.
While they are predators, they are not known to actively hunt larger animals like other whales or fish.