Question: Last year we were getting bites but had not seen the bugs. The doctor thought they were mite bites.

I see a lot of tiny, gray bugs outside on the wood railing and cement. They also jump. Could it be fleas? We have no pets but have wooded area in the back.

ANSWER  Probably what you have are springtails--but they are not doing the biting. This is a good name for them, since they hop by using their tail. They are often found in moist locations outside houses, and sometimes inside (kitchens, bathrooms, ground-level rooms). 
 
These small insects do not damage houses; they simply invade from the outside.  They are easily controlled by vacuuming or turning up the heat to dry the site.  They prefer humid locations and must have high humidity to live for very long.  They may also be controlled with the use of an aerosol spray. The best long-term solution is to dry the location and keep it dry. A hair dryer can be used to selectively dry out sites, you can direct the heat at the locations you have seen the springtails.  A dehumidifier may be helpful.

Springtails do not bite people or pets, but they can be a nuisance when they occur in large numbers.

More on springtails