Gnat Problem? Somehow, a gnat or two got into our home (probably while we...

Somehow, a gnat or two got into our home (probably while we had the door unseal for a few minutes to bring in some groceries). They are beginning to multiply--at end count, we had about 5-10 that we could find. Bug bombs are not an likelihood. Our 2 cats freak out whenever we take them out of the house. Is there any counsel about how to get rid of them once and for all--before they become a swarm?
What would be the most restructured placements for...
Answers:    Wash everything next to bleach
Do not leave garbage or pet food uncovered
Get non toxic sticky fly strips for over the sink