Because of its size, easy-to-grow nature, and the copious amounts of seed it produces, it has become one of the most common sundews in cultivation, and thus, one of the most frequently introduced and naturalised invasive Drosera species.

The secretions act as a visual attractant to nearby insects, as it shines in the sun (hence the common name of sundew).

The action itself is comparable to a person extending one arm outwards, and rolling their hand back, much like a "bicep curl".

When the prey item is decomposed enough that the plant cannot gain further nutrients, the leaf and the tentacles return to their original position.

[5] The sundew secretes mucin to trap its prey, which consists of a variety of species, including bees, small wasps, beetles; fruit flies such as Drosophila and Ceratitis capitata; Diptera, like fungus gnats and house flies; lacewings, and other arthropods.

The plant may occasionally catch aphids or mealybugs, which are drawn to the sticky leaves, as they attempt to feed on the crown of the plant—Drosera are not immune to destructive sucking insects and other pests.

It has been hypothesized that visual cues, such as tentacle coloration, could be a factor in prey attraction in carnivorous plants, in addition to the olfactory signals used.

In prey-attractant experiments, Drosophila melanogaster fruit flies were introduced to the red- and white-colored forms of D. capensi in the laboratory.

The D. melanogaster seemed to have no preference for color of plant tentacles, as there was no difference in the mean number of the flies captured between the two forms of the sundew.

[5] In early summer or late spring, D. capensis produces multiple, small, five-petaled pink flowers at the end of scapes which can be up to 30 centimetres (1 ft) tall.

[7] Drosera capensis "narrow-leaved" has won the Royal Horticultural Society's Award of Garden Merit.

Alongside Australia, California and New Zealand, Drosera capensis have also been found in peat bogs in South America.