The bags come three inside a larger bag. We freeze two for use later; no problem. As someone said, bags are more environmentally friendly, apparently. And you can still buy single liters in a carton should you choose.
Had a dog that got excited one day and jumped a short wall on our deck. Unfortunately it was a 7-foot drop to bricks below. Poor dog was stunned but seemed unhurt. It was a few years later (when she got skinny) we noticed a lump in her chest where she must have broken a rib. So, yes, they don't realize the danger.
It's about what memories it invokes... At a recent tour of an aircraft collection, the first thing our tour guide said on entering the hangar was "Ah, that wonderful smell!" All us pilots nodded our heads.
Beautiful images, but #17 isn't a sound-proof room, but a radio-frequency absorbent one. From the picture, it could be either, but I can't imagine it's both at once.