DIY busy board full of switches, latches, and doo-dads for babies and toddlers to manipulate. This is great for fine motor skills. It is also a hazard for giving escapee toddlers the skills they need to get out unsupervised.
Make a little boy a latches board. Takes just imagination, a drill, and a trip to the hardware store. It'll keep him busy for hours. - why are all these for little boys? Why can't little girls play with latches also?