Interesting tool: Omnipelagos ~ meandering search engine, finds the shortest paths between any two things. I tried the connection between cat and chocolate and this was one of the results:

Cat
[Characteristics / Hunting and diet] Cats do ingest some vegetable matter, such as cat grass or catnip. Explanations on why vary.
Nepeta
[Medicinal uses] sedatives, and as antispasmodics. They are used to alleviate symptoms such as insomnia, stress, menstrual cramps
Insomnia
[Treatment for insomnia / Removing probable causes of insomnia] and similar, chocolate bars and other candy. Drink herbal teas or plain water instead of caffeine-containing liquids.
Chocolate