The cobra lily (Darlingtonia californica) has clear cells on top of its pitcherlike trap that work like a skylight. Think about it: Would you rather enter a dark cave, or a light one?
Some pitcher plants (Nepethenes) trap frogs, and when the frogs are digested, all that remains are little matching frog slippers since the skin on frogs' feet resists digestion.
Most Nepethenes have two kinds of pitchers, some low to the ground to attract crawling insects, and some higher up to catch those that fly.