The helpless quarry is sucked inside with a rush of water. The door immediately slams shut again, with the creature inside the bladder chamber, and the digestive process begins. Because of the speed, the operation has been difficult to photograph and for many years botanists were unable to understand the process. Fortunately for people who like to swim in lakes inhabited by bladderworts, the bladder trap is only about the size of a match head, so its prey are mostly small insects and protozoans. Bladderworts are merciless with mosquito larvae, which squirm around so much they are likely to hit a trigger eventually.
Pitcher plants have highly effective pitfall traps.
In some the column is only a few inches high, but it can be almost three feet tall in the yellow trumpet. With downward-pointing hairs around the lip of the column and digestive liquor at the bottom of the flask, pitcher plants mean certain death to many insects. The bug that makes a misstep over the edge of the tube will soon become part of the plant world, as it is digested and absorbed. Sundews and butterworts, which use a form of sticky trap to capture prey, probably smell good to insects. Upon landing on the leaves, a bug soon discovers that its feet are stuck in glue.