Swallows and terns are both types of birds. Swallows are small, agile birds that feed on insects while flying. They have long, pointed wings and forked tails. Terns are also small birds, but they have more slender wings and a more pointed bill than swallows. They feed mainly on fish and other aquatic prey. Both swallows and terns are migratory birds, travelling long distances to find food and suitable nesting sites.