Hello Marge,

The insects appear to be psyllids.  They may have come from house plants if they 'just appeared' from nowhere.  Psyllids suck plant tissue and cause plant leaves to curl and turn yellow.  They are not harmful to humans but really stress plants.  There are different types of psyllids, for example tomato psyllids that only eat solonatious plants like tomatoes. 

I recommend you try to find the source.  If you find it on a house plant, move the plant outside and use a water hose sprayer to spray off the plant, concentrating on the bottom side of the leaves.  Usually you can liberate the plant easily, killing the insects with the water spray only. 

A concentration of neem oil will also do the trick.

The sticky trap is another method of attracting them to one area as you've demonstrated in the photo.  If you can't find the source, alternatively, you can kill them with a common household fly spray. 

Please do Marge.  We are here to help.

Respectfully,

Mart