Venus flytrap (Dionaea muscipula) is a fascinating plant! A carnivorous plant with a cluster of white flowers atop a leafless stalk rising above a rosette of bristly, folded, basal leaves. Venus fly-traps are native only to an area within about 75-miles of Wilmington, N.C., but they have been introduced to Florida, New Jersey and other locations.
When insects or spiders disturb any two of the six tactile bristles on the upper surface of the folded leaves of this fascinating plant, the hinged halves of the leaf snap shut, trapping the prey. A chemical secreted by the prey stimulates the flow of the plants digestive enzymes (this does not take place if the plant is stimulated by an inert object such as a pencil tip). Following digestion of the prey, the nutrients are absorbed and the leaf is reset.
The Botanical Society of America have many great facts about the Venus flytrap on their website. You will find the answers to your questions (and more) there.
Carnivorous plants live all over the world but the Venus flytrap is native to select boggy areas in North and South Carolina. Because of people's fascination with these plants, they collected many of them and they became endangered. Venus flytraps today are grown in greenhouses.
The Venus flytrap is one of the easiest carnivorous plants to grow. If you wish to grow one or more, they have only a few requirements such as, wet roots, high humidity, full sunlight, and poor, acidic soil. It comes shipped to you as a bulb or rhizome. Plant it root side down so that the top of the bulb is even with the soil. A recommended soil mixture is one that contains sphagnum moss and sand. Do not add fertilizer or lime. Your plants will do better if you transplant them into new soil every few years.
In order to provide high humidity for your Venus flytrap, plant it in a terrarium or in a glass container with a small opening. An old aquarium or fish bowl make good containers for this purpose. You need to watch your terrarium in the summer because the temperature inside the glass may get too hot. Two hours in the sun may be sufficient. If your plants wilt, then they need to come out of the sun sooner. Just the opposite is true for winter. If it gets very cold in your area you may need to move your plants away from the window or cover them at night in order to keep them warm and moist. However, your Venus flytrap will experience a dormant period in the winter, from Thanksgiving to Valentine's Day so it needs fewer hours of daylight and cooler temperatures.
Another way is to plant it in a pot and place the pot in a larger container such as a bucket. Partially cover the top of the bucket with a piece of glass or Plexiglas. Don't cover the entire top because air needs to circulate.
If you grow your plant outside, it will get enough insects to eat. If it rains the container may fill up with water but this will not hurt the plants, they can live underwater for months. If you grow your plant inside you will need to feed it insects. A couple of houseflies or small slugs per month is enough during the growing season. Do your plant a favor and do NOT feed it hamburger! Indigestion, rot may occur and usually your plant will die. Find a "just right" sized bug instead!
Also, the FlyTrapCare website has some good information about growing this plant from seed. They talk about whether to stratify the seeds or not, what type of soil is best, using rainwater or distilled water, the temperature that the seeds best germinate and how to keep the soil moist. They also have some great pictures of Venus flytrap seedlings for inspiration.
If you are interested in more information about Venus flytrap’s in the wild and whether they are endangered, we have a previous Mr. Smarty Plants question and answer about this subject.