How Carnivorous Plants get Nutrients

<-NARRATOR:-> Listen to part of a lecture in a biology class.
<-FEMALE PROFESSOR:-> Now, plants, like animals,
and like us for that matter,
need nutrients...
substances that provide nourishment...
to survive, thrive, and grow.
We get our nutrients from the food we eat.
Plants, though-
most plants anyway-
absorb their nutrients from the soil,
right, through their root systems?
OK. But there are plants that don't get their nutrients from the soil.
The places they grow, the soil is bad, so they get their nutrients from insects instead.
From trapping and digesting insects.
They're called carnivorous plants.
Carnivorous plants capture insects in different ways-they have different trapping mechanisms-
active traps
and passive traps.
A plant with an active trap . . .
ah, a good example is
the [slowly; pronounced] Venus flytrap.
The Venus flytrap actually moves to catch its prey...
or parts of it do, anyway.
Its leaves... it has special leaves that are hinged in the middle.
The two halves of the leaf open and close, sort of like
a mouth, to catch insects.
And on these leaves is a sweet nectar that attracts insects.
Insects like this sweet stuff.
And, and, when they get lured in and land on the leaf-
wham! the leaf springs shut.
It's an active trap.
And the insect springs it, so to speak-
the leaf quickly closes and forms a little cage, trapping the insect between the leaves.
The Venus flytrap is then able to digest the insect,
and get its nutrients.
But other carnivorous plants...
their methods are passive,
they don't have any moving parts to trap things.
They have passive traps.
Like the sundew plant.
The sundew plant also produces a sweet nectar that attracts insects. Its leaves are full of little hairs that secrete the sweet substance.
But what happens when insects land on the sundew's leaves to get at the sweet nectar?
Well, unfortunately for the insects,
the hairs on the leaves also produce a super sticky, glue-like substance-so an insect gets stuck in them and can't fly away.
It, it basically gets glued there,
allowing the sundew to digest it
and absorb nutrients.