Birds migrate for reasons such as finding more food, dispersing their young, avoiding predators, and seeking more favorable climates. They navigate using the sun, stars, and landmarks, and possibly a magnetic sense. Migration is studied using bird ringing where birds are caught, tagged, and released to track their movements. Migrating birds face challenges including harsh weather, lack of resources, and threats from other birds and humans. Activities to teach children about bird migration include making bird houses, reading books, bird watching, marking routes on maps, art projects, and learning about climate and predator risks birds encounter.