The Venus Flytrap (Latin name Dionaea muscipula) is a carnivorous plant originating from just one place in the world, a 700 mile region along the coast of North and South Carolina. Even within this area, they are only found living in humid, wet and sunny bogs and wetland areas, and their scarcity led early scientists to believe they were mythical. The plant's diet consists mainly of spiders, flies, caterpillars, crickets and slugs which it first lures, then captures and finally digests.
To attract a prospective lunch, the Venus flytrap secretes a sweet nectar onto its leaves. When a soon-to-be-ex-bug notices this, it lands on the plant and comes in contact with the six trigger hairs on the flytrap's leaves. If these hairs are knocked more than twice, the trap closes around the unfortunate victim (this takes around 1/2 a second). Next the plant senses whether the captured prey is alive (and therefore edible) or if it has just been triggered by some interfering botanist, by checking to see if the hairs are still being stimulated when the leaves are shut. If the hairs aren't stimulated the trap opens, an operation which takes around 12 hours. If the plant thinks what it has caught is edible, then seals the edge of the trap completely and secrete acidic juices into the airtight pocket which dissolve the soft tissues and cell membranes of the food. The insect is bathed in these juices over a period of 5 to 12 days (depending upon its size), during which time the contents of the trap are digested and nutrients are extracted. Each trap lasts for around 12 operations before opening out permanently and starting more normal plant like behaviour, photosynthesis.
The reason that the plant goes through this rigmarole of bug catching is due to the acidic soils it lives in, and the fact that there are very few nutrients for healthy plant growth contained in it, so insects are an alternative source of required chemicals.
The flytrap part of this plant's name is fairly obvious, but the Venus section of the name is slightly more confusing. According to the International Carnivorous Plant Society it came about as follows:
The origin of the name is quite lurid. The Venus Flytrap was first studied in the 17th and 18th centuries, when societal mores were a bit more puritanical than they are today, and were somewhat obsessed by human urges and sins. Women in particular were often portrayed as temptresses, greedy for power. The botanists of this time apparently found a parallel between the trap of the plant -- capturing and digesting insects -- and certain aspects of female anatomy and behavior. Thus, the story goes that they named the plant after Venus, the pagan goddess of love and money.