I have gnats and can't get rid of them... I have a dehumidifier and sticky strips, but they are not working!

You will need to find the source and remove it. It could be drains, potted plants or even the drip pan under the refrigerator. Tape the drains shut with clear tape. If gnats are found on the underside of the tape, then that is where the problem resides. There are products with enzymes that breakdown the organic material (otherwise known as slime), eliminating the breeding source.