Instruct: Classify the given review into positive or negative sentiment.
Query: Stuff I would have liked to know

I bought this and a refill pack to take care of an ongoing fly problem at work (indoors).What you should know is this: the "attractant" that you mix with water smells like spoiled fish and eggs. It smells when filling the trap and smells when emptying it. As days pass, the smell gets stronger. This is what attracts the flies, the smell. This won't be something you would want to use indoors. Flies don't exactly fall prey to this trap either. Some will land it on and fly away.There are more effective products out there. It's a messy and very smelly solution that's only partly effective.