Sorry- posting in AIBU for traffic and as I don't really know where else fits.
We live rurally, there is a river close and a pheasant shoot locally (so food bins dotted around the fields) -we have a few chicken about 100m from the house, and historically (20years ago) dogs were bred by the NDNs.
My cat killed a few young rats in the summer, outdoors. And I assume attracted by the chickens.
It has been very cold the last few days and on 2 occasions we have seen a young rat in the house.
Now everyone says 'there is never just one rat' and I am waiting for pest control to ring me back, but I'm quite worried- is it possible that these 2 rats have been 'passing through' (driven in by the cold) or am I actually completely oblivious to the fact that my house is probably overrun with rats?? 
(not envy-obvs)
We are quite a large household and there is someone here, making noise all day, 3 cats.