[Ghoulish Delight]

It's swaddling. It's something very very old that us advanced modern folks are just now relearning (fell out of favor in America around the time of the Revolution - wouldn't want to restrict your baby's freedom now would you?)

A lot of people think their baby hates it because, especially the first few times you do it, they seem to get pissed off while you're wrapping them up. But once you figure out how to do it, and combine it with a couple other things (get them in the right position, rock them just right, shush them in a white-noise sort of way), it can literally be like an off switch for an inconsolable baby. The working theory being that infants have a reflexive response to stay calm in womb-like conditions since throwing a fit in the womb would be generally bad. What's are womb-like conditions? Wrapped up tight, kinda lying on their side, jiggling around as mom moves, and the constant white-noise-like din (about as loud as a vacuum cleaner) of blood rushing around. Recreate that as closely as possible, and you have a calm baby.

Of course, "primitive" cultures, without the benefit of knowing WHY it works, figured that out all on their own. Wrap 'em in a papoose, strap 'em to your back so they bounce while you walk. It's been working for millennia.