Have you ever seen a shark swimming in the ocean with a small fish or group of fish swimming really close by? Or maybe you’ve seen a zebra with a little bird sitting on top of it. Both display symbiosis, which is when two organisms in close proximity develop a relationship.These animal relationships may seem peculiar at first glance, but they are important for the species involved. Remoras swimming with sharks score a meal and protection from the shark in exchange for keeping the shark and its environment clean. In the case of the oxpeckers seen on zebras and other grazing animals, the birds gain access to a host of ticks, flies and other potential mammal parasites to eat while keeping the grazing animals clean and calling to warn them when danger is near.