Those who can successfully teach the little ones are worth their wait in gold!
Do some research into methods such as Suzuki, Orff, and Kodály. Although they are not drum specific at all, I think these methods could work for drummers too.
I’d suggest as Johnathan said, let them be kids, and make it fun and engaging. In the early stage, I believe that a big emphasis should be placed on aural skills, rather reading. Our art form is aural, and if a musician doesn’t have good ears, they will have severe limitations. That’s why I think note reading should introduced after a sense time and strong aural awareness is developed.
i had my daughter in a toddler music program at the University of Texas, taught by a doctorate professor, who is a recognized expert in early childhood music education. She had a group of little ones having so much fun, and learning music too, through play, singing and dance. At age four, my daughter then went on to Suzuki violin. The teacher insisted that she didn’t learn to read music until she could play a substantial amount of songs by ear/ rote. It worked out well for my daughter, she is now 20 and has won some concerto competitions, performed at Carnegie Hall and toured the USA and Europe with a string quartet. She gigs with a mariachi group, and country band (no sheet music- perfect pitch and a good sense time helps) and also is playing in pro orchestras where she has to read everything. Even though she was accepted in some very prestigious conservatories, she chose to stay in state for college. She plans to to work with kids as a counselor, and have a sideline music career too.
Sorry to brag, yes I’m proud, and I’m trying illustrate what a good early start in music can do.