Pitcher plants have leaves which turn sunlight and carbon dioxide into sugars, just like trees or flowers.

Though, the pitcher itself can sometimes eat bugs. The bugs are attracted to the sugar in the pitcher, then they slip in and are slowly digested. The reason that some pitcher plants eat bugs in addition to collecting sunlight is that the energy from the sun isn’t enough for them. To make sure they get all the food they need, they need to eat bugs as well as get energy from their sun.

Pitcher plants get light from the sun like any plant. Most plants get other things (called "nitrogen" and "phosphorous") from the soil that they need to use the sun's light, though, which pitcher plants can't. Pitcher plants get these other things from insects that they eat.