Can someone sue a company if they found flies in something they were eating?

I would need more information. However I believe the answer is probably not. The FDA allows a certain amount of bug parts in food knowing that is impossible to keep them out completely. The FDA has a long list of Food Defect Action levels. For example, 225 bug parts are allowed in 225 grams of pasta. Anything less is ok. Also a determinative factor is the health risk. In other words, rodent hairs and fly parts are regulated differently than rodents and maggots when it comes to what is allowed in your food. You would have to overcome the hurdle that the fly or flies in your food reached a Food defect Action level for a foreign product in food. If you were able to prove that , then you would have to prove you were injured. Personally I find it hard to believe that anyone could get so sick from eating a fly in their food that it would ever justify the expense of pursuing this uphill battle. The costs of pursuing this claim would far exceed any potential verdict or settlement.