When spring comes to Europe (March to May), the weather gets warmer. Snow and ice melt. Baby fish and insect larvae swarm in the streams and ponds. Migrating birds return to make their nests and raise their families. Flowers open and bees carry pollen from one plant to another. Trees put out new leaves which catch the sunlight and use its energy to make the tree grow. In mountain regions, farmers move their cows up into the high meadows, where there is now plenty of fresh grass.