Aphids can’t bite people, pets, or eat plants because they don’t have a mouth or teeth. But aphids have sharp mouthparts that they use to pierce plants and suck out sap. If an aphid thinks you might be a plant or feels threatened, the aphid could pierce your skin with its needle-like mouthparts.

Can aphids bite?

Aphids have needle-like mouthparts. They use the mouthparts to pierce tender plant parts and consume the plant juices. Aphids can’t chew and therefore, can’t bite.

Do aphids hurt?

While a high concentration of aphids on your milkweed may look “bad”, these insects are not necessarily causing harm to monarchs; unless they are in extremely high density, there are usually not enough aphids to kill the plant.