Litter training a family of 4 bunnies - help!

Hi, I am new to this site and come in need of help.
I have 4 mini lops - the daddy (4), Mummy (2) and two babies (9months). They are all spayed/neutered.
They live in a converted shed with an attached run. they live all together and are very happy happy bunnies.I bring them in the house and they hop about and use a litter tray for wees.
My only problem is that they will not poo in the litter tray, instead they poo anywhere and everywhere. In their shed they poo everywhere and in fact wee wherever they like too - usually in any corner, in the litter tray, anywhere. IN the house they wee in the tray (phew) but they leave pellets everywhere.
How can I train them to poo in the trays? I can cope with the shed, I just have to clean the whole thing out a lot but would really like them to poo in their tray in the house!
Thanks for any help

best way I found is to just keep putting the poo in the litter box, but also to look if there is a specific place they poop more than other and put another tray there. you may initially have your house littered with trays, but once they are used to it, they will keep going there. but first thing to do is to keep putting the poo in the tray, and in the shed if you can try and soak the wee up with some tissue and put it in the tray too. they quickly should train themselves

Hello and welcome and I think it is lovely that you have kept them all together in a little family group, Because rabbits are family animals. I think because rabbits are very territory minded this makes it really difficult to get them to do everything in a litter tray as they want to keep marking their territory. Also because they live outside but come into the house occasionally will only add to their deeply ingrained insticts to claim this territory as well.

Thanks. Yes I love our little bunny family. I got them in February and loved the dad but wanted babies, and also wanted daddy to have a pal so took the mum as well! All from a breeder. So you think it's a hopeless situation and I should just accept the little presents they leave me?!