Not unless your rats have been unlucky enough to get an infestation of snake mites in their ears. Most mites can live for a short while on another host but not long (eg. snake mite protonymphs {i think} can indfest humans). I would be more worried about whether Africanciclidau's can get infested with ear mites!
Cheers Maggie, that has put my mind at rest, (yes I have got one but it's only small), I'm not worried about getting them myself cos if I do I'll just stick my head in a bucket of "Top Of Descent"
Thanks again mate