Why potty box train?  Our babies need an area that they recognize as their spot while they are still in the nursery.  We do introduce outdoor training, once they have received their vaccinations.  From 4 weeks -6 weeks, someone is with them around the clock to put them in their potty box when they show signs of needing to do their business.  Once they hit 6 weeks, they can recognize their potty box and they will start to use it themselves.  It's the neatest thing to watch unfold and we are so super proud of them!  We have used pet pellets, regular litter, and wood chip shavings before.  We feel that using the wee pads in their potty box has been a much smoother alternative for them and it doesn't encourage them to lay in like the other options have, previously.  A few of our families still use the litter box for their adult Cumberland Cavapoos.  It's great for bad weather alternatives, or if you live somewhere there may not be a lot of green spaces.  A grass pad in a litter box is another great alternative.