DS4 is pretty responsible, so when he needs to be entertained he's gotten past the point where he can find an activity for himself or he's on a learning kick and we're trying to keep him from the activity that he thinks is a good way to learn whatever it is he needs to master.
Here are a few substitutions - we could use them a few days to a month entertainment wise but at least he didn't go back to the previous 'entertainment'
Grabbing drinks that fiz ->
Glass of Apple cider & cup baking soda with a bowl, (buy the gallon & large box this is good for hours with refills)
Disasembling the microwave -> The Way Things Work software
Rewiring electronics (phones, computer) -> Snap circuits
Doing laundry/dishes -> um, we just walked him through that
Pouring drinks on the floor (at 1) ->
Two pop bottles filled with seeds/beans taped together
