Hi Dans- once a ewe has a lamb(s) she is fine to bring in just with the lamb(s)- she will not feel lonely. In terms of culling your 'empty' ones now- I definitely would not do so. It could be that they took late or your scanner has made a mistake...or lamb is just too small to see. This of course could also be the case with your 'singles' so just have it at the back of your mind that they could still be a twin (if the afterbirth has not been passed after a short time). It is really difficult to determine if they are pregnant by the outward size of them- even days before lambing in some (the lambs can be tiny- particularly ewes- and 2's and 3's). The udders, however, are a good guide and will begin to swell ('bag-up') a few weeks before (which is when you should begin to keep a very close eye on their behaviour). In fact no bagging up means that that they are no way near lambing and you can relax for a while. Mine are always later than expected. Exciting times! I'll PM you my new mobile no.!