Whales spend the winters in Hawaii playing around and having a good time. They they travel a quarter way around the world, going to the cold north for the summer. What's wrong with Hawaii?

 

In the Arctic Circle there is a lot of permafrost. This ice melts in the summer with 24 hour daylight, leaving puddles of water. Mosquitoes grow in this water. Birds and ocean life eat these mosquitoes, and so there is plenty of food for the whales. You see how small things like mosquitoes can affect huge things like whales!

 

In the winter they go south, to play around, have sex, and raise their young.