Abdomen - the last segment of an insect's body, located at the tail end. The heart, reproductive organs and much of the digestive systems are located in a butterfly's abdomen. 

Adult - the fully grown or fully developed stage of an animal. (A butterfly is the adult stage of a caterpillar.)
Antenna - one of a pair of slender structures located on the heads of butterflies. These antenna are used for balance, detecting smells and determining 
Basking - the activity where a butterfly rests with outstretched wings in the sunshine in order to absorb as much heat as possible. 
Camouflage - a protective coloring that enables a butterfly to blend in with its environment, thus hiding it from predators.
Caterpillar - the worm - like second stage in a butterfly life cycle also called a larva 
Chitin - (Pronounced: Ki - tin) - a tough, colorless material that makes up the butterfly exoskeleton.
Chrysalis - the third stage of the butterfly life cycle, also called a pupa.
Cocoon - the silken protective covering made by a moth larva before it becomes a pupa.
Cold Blooded - having a body temperature that is about the same as the surrounding air because of the animal's inability to regulate their own internal body heat. On the other hand, their bodies stay at a fairly constant temperature, regardless of their surroundings. 
Dormancy - a period of no activity, when development is suspended, often occurring during unfavorable conditions.
Egg - the first stage in a butterfly's life cycle. The larva or caterpillar hatches from a butterfly egg.
Exoskeleton - a tough, external covering made of chitin, which supports the body and protects the internal organs.
Head - the front body segment of a butterfly. The mouth parts, eyes and antennae are located here.
Hibernation - also referred to as overwintering, the act of entering a time of dormancy or inactivity that lasts through a specific period of time (such as a season), enabling a butterfly to survive through a severe winter. Butterflies that hibernate in the winter may do so at any stage of development, depending on the species. Most often, however, hibernation occurs during during the pupal stage.hibernation 
Instinct - a way of behavior that is natural to a butterfly from birth. The behavior is known without having been taught.
Larva - the worm - like second stage of the butterfly life cycle, also called a caterpillar.
Life Cycle - the phases or changes that a butterfly goes through from the egg stage until its death as an adult.
Mandibles - tooth like jaws present in insects with chewing mouth parts. (Caterpillars have mandibles, butterflies do not.)
Mating - the pairing of a female and a male in order to breed and produce offspring.
Metamorphosis - the marked changes in appearance and habitthat occur during development, from the growing stage (s) to the mature adult stage. Butterflies undergo "complete metamorphosis" and their appearance changes completely from the larval to the adult stage. (Insects which go through a "simple metamorphosis", such as a grasshopper, change only gradually in appearance during these stages .
Migration - the mass movement of an animal species across many miles in order to escape unfavorable conditions. Some butterflies such as the Monarch, may migrate thousands of miles in order to avoid winter conditions. Other types of butterflies may only migrate a relatively short distance.
Molt - to lose the old skin or exoskeleton. The butterfly grows a larger one to replace the one that is shed.
Nectar - the sugary, sweet liquid produced by many flowers.
Ovum - egg.
Patrolling - flying over a specific area in search of a mate.
Perching - landing on a tall plant or other object for the purpose of searching out a mate.
Pheromone - a chemical given off by an animal and meant to cause a specific reaction in another of the same species. (Butterflies give off pheromones in order to attract a mate.) 
Proboscis - a straw - like, flexible tongue that uncoils when the butterfly sips liquid food and then coils up again into a spiral when the butterfly is not feeding.  
Proleg - a fleshy leg or "false leg" attached to the abdomen of certain insect larvae.
Puddling - sipping nutrient - rich water from puddles. Generally more males than females puddle and it is believed that the salts and nutrients in the puddles are needed for successful mating.
Pupate - To turn into and exist as a pupa.
Scales - tiny modified hairs which overlap on a butterfly wing. The scales give the butterfly wings their color and beauty
Stage - one of the distinct periods in a butterfly's life. (Butterflies have four stages: egg, larva, pupa and adult.
Thorax - the second segment in a butterfly's body, located in the mid - section. Butterfly wings and legs are attached to the thorax. 
Vein - the rib - like tubes that give support to the butterfly wings. (The veins are tubes, mostly filled with air.)