They can also go on the side of the road, with the added hassle of disposing of paper. Where do you think they use the bathroom when hiking or camping? And this

They can also go on the side of the road, with the added hassle of disposing of paper. Where do you think they use the bathroom when hiking or camping? And this is why I included cups in my original comment. They can't use bottles as easily on account of the narrow nature, so a cup with a larger mouth is preferred.