Cats dislike the smell of oranges because oranges contain essential oils from the peel, a volatile aromatic hydrocarbon with a strong odor. Cats have a more sensitive sense of smell than humans, and are especially sensitive to pungent smells. The pungent odor of oranges makes cats uncomfortable. If a cat accidentally smells an orange, it will immediately recoil as if electrocuted, wrinkle its nose, pout, and show disgust; it may even gag. 
Things cats dislike:
1. Camphor balls. Camphor is toxic to cats and can cause acute camphor oil poisoning, which can lead to death. In addition, the strong smell of camphor balls is also disliked by cats.
2. Sour things, like vinegar and lemon. Cats feel uncomfortable whenever they smell sour things, as if there's something in their nose.
3. Litter boxes that are not cleaned in a timely manner. Cats have very high requirements for themselves and their surrounding environment. If the litter box is not cleaned in a timely manner, some cats will find it too dirty and will not bury their feces, or they will simply refuse to use the litter box and defecate anywhere else.
4. Garlic smell. Garlic is a forbidden food for cats, and they also dislike its smell because it contains sulfur compounds that produce a pungent and irritating odor, which cats find unpleasant.
