Insect stings are common in pets, especially in dogs. Stings are not a major problem for most pets, but some pets (just like humans) will develop an allergic reaction.
Have you noticed your rabbit scratching? losing fur? developing dandruff? It’s possible they could have a skin parasite (fleas, mites or lice).
Fly strike happens when a fly lays its eggs on a rabbit’s fur which hatch into maggots and burrow under the skin to feed on flesh.