Source of Nutrients
Carnivorous plants are looking for certain nutrients, and have adapted to trap their prey and digest it with enzymes it produces or by use of bacterial enzymes.
Nitrogen
Though a majority of plants are mostly seeking nitrogen, this is no different for carnivorous plants. Insects can provide a great deal of what these plants need.
Other Nutrients
Insects also contain small percentages of potassium, calcium, phosphorus, magnesium and iron. Certain genus value the phosphorus in insects. Bladderworts, an underwater plant, are some of the largest carnivorous plants and value magnesium and potassium.
Common Insects Eaten by Plants
Mosquito larvae are a common insect trapped by many carnivorous plants that grow in water, but these might also ingest fish fry, rotifers and daphnia, according to the International Carnivorous Plant Society. More common insects caught or trapped by these plants are ants, beetles, moths, flies, spiders and wasps.
Easy Plant Prey
Insects happen to be prime food because of the way they crawl, fly or swim into them.