Bowtruckles are considered omnivores. They mostly eat woodlice due to their availability. Woodlice, the singular version being woodlouse, are crustaceans with long, segmented exoskeletons, and fourteen limbs. They are more known by their common name, roly-poly because they can shape themselves into almost a perfect sphere. When lice are not available, Bowtruckles may eat other insects like aphids, or consume leaves in the absence of insects. Bowtruckles, while enjoying woodlice, are better won over with fairy eggs. Fairies lay their eggs on the undersides of leaves. A fairy can lay an average of fifty eggs at one time.

Fairy eggs are considered a delicacy to Bowtruckles because even though they live in the trees where fairies lay them, fairies are very vicious in guarding their eggs and it is highly unlikely that a Bowtruckle will be able to steal any on their own. Offering the Bowtruckle anywhere between twenty and thirty eggs will take the Bowtruckle's attention off of you for about twenty minutes because they take their time to taste the delicacy. When attempting to use fairy eggs as a distraction, it is best to have enough for two or three meals, as the Bowtruckle will keep eating the fairy eggs until there are no more provided, and you may want to have as much time as possible, depending on the type of wood you are attempting to take and your experience level in collecting wood. Bowtruckles love to gorge themselves on fairy eggs. They can actually give themselves a stomach ache, but this doesn’t stop them from eating them.