Pam found them hiding under the seat pads of the chairs after noticing some rather nasty stains on them.
Having removed the pads to wash them, the kittens have now taken up residence under the garden shed.
We are pretty sure that the mother is returning to feed them because they are growing in size.
Whilst they are clearly adorable, we do not want them to stay and so are leaving them alone and certainly not offering any food. At the same time, we would not want these kittens to come to any harm.
Any suggestions as to what to do would be very welcome.