All living creatures are known for adapting to changes in their environment, their food sources, and climate. Animals (and people) do whatever they have to do in order to survive, including working with others. Over time, symbiotic relationships are built - but what does that mean?
The term symbiotic relationship, in this case, means that two different species work together, and they both benefit. It's kind-of an "I'll scratch your back if you scratch mine" deal - but usually, each party involved doesn't really know that they're helping the other.
Whether these animals stumble upon a new symbiotic relationship by luck or they are taught by their parent(s), working together ensures that each one will survive (or at least have an easier life). Each animal's "other half" in the relationship is called a symbiont.
Lots of animals work together in the wild - fish, mammals, and insects. Everyone who has seen Finding Nemo has witnessed a symbiotic relationship at work: Nemo and Marlin lived in an anemone. Although Nemo couldn't pronounce the name of his home, both species benefited from the help of the other. Marlin and Nemo (although not depicted in the movie) are a type of very territorial fish, which protect anemone from predators. It's hard to believe that anything would want to eat an anemone, but if something does, the clown fish swim out and attack. The anemone's stingers protect the clown fish from their predators, too - so it's a win-win situation.
Symbiotic relationships aren't just animal-to-animal, either. An animal-plant relationship can develop, like in the case of bees and flowers. Bees land on flowers and gather nectar, which they turn into food. Good for the bees, right? But it's not one-sided. When a bee gets nectar, he also gets pollen on his body - when he goes to the next flower to get some more nectar (greedy little thing, isn't he?), he inadvertently drops off the pollen from the first flower. That benefits the second flower, because now it's been pollinated and can reproduce.
Over thousands of millennia, these relationships have developed in nature. Some experts say that it's based on Darwin's "survival of the fittest," while others contend that a higher power designed symbiotic plants and animals to be co-dependent on each other. Regardless of how it all began, one fact remains constant: some of the symbiotic species would be in grave danger of extinction without symbiotic relationships.