My cat is leaving yellow oval things where she lays. What are they?

Those could be tapeworm segments. Also possible is some sort of fruit seed. The head of the tapeworm is buried in the lining of the gut. Reproductive packets break off the other end of the worms and pass out with stool or can crawl out of the rectum on their own. When they dry up, the look like seseme seeds. Tapeworms are only spread by eating fleas. Over the counter tapeworm dewormer does not commonly get the type of tapeworm that cats tend to get so I recommend to see your veterinarian, bring in a fresh sample of your cat’s stool as well as some of the yellow objects. Dani will need to be treated for fleas as well. I hope this is helpful!!! Please post again with any further questions!