Use hydration bags for kids to carry water and food. It will free up their hands for other things like picking berries and exploring. It will also get them use to carrying a bag on their back and slowly introduce them to backpacking over time. I found that with my own kids, they got tired of carrying a water container and the containers were too heavy to clip to their pants. I bought cheap hydration bags from Sam’s Club at the end of the season. I think I ended up only paying $15 per bag. I threw out the plastic bladder bag because it was a cheap plastic and I couldn’t remove the plastic taste and some of them leaked. I prefer to use Stainless bottles anyway. We just place the bottle in the area where the hydration bag would go and place snacks or any other items in the other pouches. There is also a nice little pouch inside of these bags where I place an emergency blanket for each child. That way if something happened where all or any of us got lost and had to spend the night in the wilderness unexpectedly, we would each have some shelter from wind, rain and cold. I like these bags better than other more expensive bags because there is more storage than a standard hydration backpack and they were a lot cheaper. They are a cross between a small hydration pack and a small backpack, perfect for our purposes. Someday I plan on doing a lightweight backpacking trip using one of these packs just to see how well it would work. I’ll let you know how it works out. Have a great time enjoying the wilderness with your kids.