Tiny bugs in my bearded dragons cage in the Walnut Sand?

I have just switched my bearded dragons cage over to Walnut Sand now that he is a year old which I was recommended to by a reptile specialist at the pet store. Now over the last few weeks I have started to notice that there are tiny little red beetle looking bugs crawling around his cage. They seem to be red in colour and have tiny wings. They also seem to appear only when water has been spilt in the cage from his large water bowl. What are these tiny bugs, how can I get ride of them and are they dangerous for my bearded dragon. Ps: I know for a fact that I can already rule out mites.