Hope things are going ok for you! The only thing i would suggest is to keep them contained in one room over night, with litter trays bed and toys. Try to contain them to one room during the day if you can, at least for now
They may just be a bit overwhelmed at having the run of the house. Watch them closely during the day (if you are at home) and if you see them about to toilet anywhere other than the tray promptly pick them up and place them in it. Also clean the spots they have already used on carpets with washing powder and warm water to get rid of the smells. If they can still smell thier own wee they will continue to keep going back to that same spot.
Also make sure the trays are cleaned daily, scoop out any mess including the wet litter and do a full change every few days. This should help as they dont like dirty trays.
Has anybody got any tips on how I can get my kittens to use their litter trays please? I got my two lovely ten week old kittens yesterday and they seem fine, having explored the house, and last night they slept on my bed with me so I don't think they are too stressed or scared. However they just will not use their litter trays! I woke up to two little piles of poo in my living room (right next to the tray!) and several damp patches in various corners of the house. The lady I got them from did say they were litter trained and I know it's probably down to a change of environment but I wondered if there was anything I could do to help them along? I am using the same litter they are used to, they have a tray each, and I show them their trays after they have eaten but can I do anything else? Many thanks