If they are hanging around your house plants, they are probably fungus gnats.  Get yourself some fine sand–buy a bag of kids play sand if you don't have a sandy area outside.  Put the sand on top of the soil in the pot, about half an inch deep–remove some soil, if you have to.  The larvae are in the potting soil, and the sand keeps them from reaching the surface to hatch out.  Works like a charm.

Gnats in the bathrooom may be 'sewer flies'–they don't come out of your sewer, but they do breed in the gunk inside drains.  A potful of boiling water will kill the larvae in the drain–nothing else works very well.  Those gnats are bigger than than the fungus gnats.

If your plants will allow it, let them dry out a bit–only water when the top inch or so of soil dries out.  That will discourage the gnats.  (Some plants object to this.)

Vinegar (or a little beer, or some fruit juice and yeast) does work for fruit flies.  I make a fly trap from a jar with a piece of paper folded into a cone stuck in the top.  The juice/vinegar attracts the flies, they go down into the cone and enter the jar, but try to fly out of the top of the jar.  Use a piece of tape to seal the cone to the top of the jar.

(I work for U of MO Extension–we get bug questions all the time, and I hate to tell people to spray insecticides–much better to use other methods.)