You need to inspect and check between scales and around the eye socket this is where those little black bug will be the most visible.

It is however possible that no mites are visible at the time of purchase and an infestation breaks out 30 days later all you need is to have eggs on your BP and while mites can be spotted more or less easily, eggs are not that easy to spot.

Serious infestation can lead to death, you also have to remember that mites can be the vector for the transmission of various diseases.

The best thing you can do is to make PAM (Provent A Mite) part of your quarantine routine, always have a can available and always treat all new purchased regardless of the source.