Here's a cool Lifehacker hack for a fruit fly trap just in time for summer. If flies still linger after doing the obvious – tossing overripe fruit, taking out the trash, cleaning up, and cooling down the kitchen – it's time for the trap. To make it, simply pour some apple cider vinegar into a small microwaveable bowl and top it off with a few drops of dish soap. Microwave it for 30 seconds, and then set it out on the kitchen counter. The soap breaks the water's surface tension, making it easier for the flies – attracted to the sweet-smelling vinegar – to step on the fragrant liquid and fall in.