I agree w/the Springtail ID. I has a monster infestation of ...at the time I had no idea what... in some tropical houseplants a few years back and it sent me on a search. Your little critters look exactly the same to me.
What I found out...they are more annoying than harmful...in most situations. For the most part, in regular soil type plants and outdoors in our gardens, they are an indication of a health eco-system. HOWEVER...their being in your orchid pot could be a possible indication of too much moisture.
Here's a great link to learn more...
http://agrilifebookstore.org/tmppdfs...c5e3c87d541858
Hope this helps!
Kat ~
