A view of the relationship between ants and aphids.
Many insects develop symbiotic relationships with other organisms to help defend them in their environment. These relationships are mainly mutualistic. An example of this type of relationship is between aphids and several ant species. The aphids provide honeydew to the ants while the ants will take the aphids into their nests at night to protect them from predators and escort them back to a plant the next morning. This ant species has even been seen collecting the aphid's eggs and placing them in their nest's storage chambers to survive the cold winter months. Another example of defensive symbiosis is between an Amazonian bee species, Schwarzula and a species of scale insects called Cryptostigma. The bee species nests in a hole in a tree previously occupied by moth caterpillars. This opening also houses around 200 of these scale insects. The scale insects feed on the tree sap and excrete honeydew. The bee will lick up this solution for its nourishment and in turn keep the scale insects from drowning in their own waste. Yet still, the blue-winged butterly in Northern Europe and Asia exists by its symbiotic relationship with an ant species from the Myrmica group. The caterpillar form of the butterfly excretes a honeydew solution which the ants crave. The ants will take the caterpillar back to its nest where they will look after the caterpillar over the winter. When the weather warms, the caterpillar pupates and then crawls from the nest to mate and lay eggs on certain plants.