Having been involved on and off for the last 40 years with Boy Scouts I can say that they do start with knots and lashing early on (11 years old). I think the Cub Scouts do some even younger. The first few Boy Scout ranks (Scout, 2nd Class, 1st Class) all have knots and lashing requirements. Beginning with Square Knot (Reef Knot), and continuing with whip and fuse the ends, two half-hitches, taut-line hitch, sheet bend, bowline, timber hitch, clove hitch, square, shear, and diagonal lashings. Then there's the Pioneering merit badge. I always make them practice until they could tie the knot behind their back so they could do it in the dark and could understand how the knot was formed by seeing it in their mind.
I agree that the Animated Knots website (
www.animatedknots.com) is excellent, but I'm prejudiced 'cause several years ago I suggested a tip on how to pull the frappings tight on lashings and he included it and gave me credit. There's also a great Animated Knots phone app for when you're out in the wilderness and can't quite remember how to tie that Alpine Butterfly Loop or Trucker's Hitch.
This brings back lots of memories of one-handed bowline contests with scouts and getting a good laugh as they either fall one their rear or squish their fingers in the knot when they lean back when they're not quite finished.
For those who don't know about one handed bowline contests, I'll explain. Tie one end of a 8 or 10 foot rope to a tree about eye height. Face the tree. Pass the loose end around your waist and grab the end with one hand. At the starting sound use the one hand to tie a bowline with the end in your hand and the section of the rope between you and the tree. When you think you're done let go of the rope and lean back to about 45 degrees so that the rope supports you. Just remember to pull your fingers out BEFORE you lean back.