Sundew plants capture and digest insects. Their leaves are lined with sticky hairs containing a digestive enzyme produced by glands in the leaf. When prey land on the plant, they are wrapped up by the leaves, and glands secreting the enzyme begin their work. Some varieties of sundew actively trap insects, curling around them as they struggle to insure maximum contact with the deadly enzyme.
Sundew plants are found on every continent. Growing in wet, acidic locations, carnivorous plants such as the sundew have difficulty obtaining all the nutrients they need from the soil. Essential nitrogen must be obtained by other means, thus the plants have evolved to capture and digest the nitrates in insects.
In order to lure prey, most carnivorous plants have developed bright colors, guide hairs or leaf extensions. The prey is tricked into believing the traps contain nectar. Some plants trap their pollinators, but do not receive nutrition from the insect. These are not true carnivorous plants.
Carnivorous plants do not obtain all their nutrition from the trapped insects. They can still create energy from sunlight and use the insects as a supplement. However, the plants will grow more vigorously when insects are added to the diet.