You can easily tell if you have phorid flies...they rum across surfaces in a stop 'n go motion rather than flying.
There are a few things of "importance" in knowing if its phorid flies or gnats.
Gnats are not spreaders of disease as a rule...they tend to fly more phorid flies do.
"Because it frequents unsanitary areas (with the ability to spread disease-causing bacteria onto food products), this fly is of particular concern to hospitals, healthcare facilities, and restaurants. Open wounds of patients in healthcare facilities often house phorid fly larvae"...
https://www.doyourownpestcontrol.com/phorid-flies.htm
Phorid flies can destroy your chameleon eggs without you even noticing until it's too late.
They can get into the fridge or sealed containers that you would never believe they can get past the seal/gasket of....so you really want to get rid of them.
They move rapidly...like to fly at your eyes (can cause conjunctivitis) jump into your food...breed in your garbage can...sit on poop...etc.
They are so hard to get rid of because they like moisture, will get into the food you're providing for the insects, live in your drains.
Hope this does t scare anyone!
Hope you get rid of them ...no matter what they are!