Some mites have made an unexpected appearance amongst my house plants. I suspect they're predatory mites as they are relatively large and quite mobile. There's no sign of leaf damage or webbing typical of a spider mite infestation. If they are indeed predatory then they're most welcome to stay. However I don't see how they'll survive without the bad mites around. I have occasional outbreaks of those but they're quickly dealt with while in their early stages. One of these mystery mites was first spotted in a plant which I bought in the summer but I didn't think much of it at the time. This same plant became infested with spider mites in the autumn so it probably came with a mix of both types of mites. There was no sign of mites after several treatments with insecticidal soap. Then a large number of these mystery mites appeared in the pot sometime afterward but then disappeared just as quickly. Today they were seen in another pot some distance away but not in any other pots. (Are they going from one pot to the next in a group looking for prey?!) Has anyone had a similar experience? Any opinions?