Please be cautious about reporting them, as they may end up having to be rehomed or put down. If they are being seen to three times a day then they are obviously cared for, and they may be the type of dogs that don't carry a lot of weight such as lurchers or greyhounds.
I have a neighbour who has reported me to the RSPCA three times for 'abandoning' my dogs, he does not know when I come and go and the RSPCA inspector has been out three times and said there is absolutely no welfare issue. I am not a big fan of the RSPCA but he is only doing his job and has to follow up any complaints. It has got so bad I have reported this person to the police for harrassment and threatening behaviour (he threatened to kick my door in and let the dogs out). I too have several oldies who sleep most of the time, although they all enjoy their runs over a huge airfield several times a week.
Keep an eye on them and try to find out a bit more before you report them to anyone.