[Question] Good brainteasers for children?

I love asking children (and adults in some cases) the following question:

Five birds are sitting in a tree. A hunter takes a rifle and shoots one of them. How many birds are left? (Edit: Rephrased to avoid several problems)

Five ducks are sitting in a field. A hunter shoots and kills one of the ducks. How many ducks remain sitting in the field? (If your answer is ‘four’ - try again!)

This is a system I/​system II trap, akin to “which weighs more, a pound of feathers or a pound of gold?” In my experience kids (and adults) usually get this wrong the first time, but kids get a special kick out of something that sounds like a math problem they do for homework but turns out to be a bit more. I’ve also used the 2, 4, 8 puzzle for impromptu demos of confirmation bias. These are fun and engaging ways to teach kids about cognitive biases before they could realistically read the Sequences or Thinking Fast and Slow.

Can we share or brainstorm any more? Some basic inclusion criteria (feel free to argue or suggest more):

  1. Problems/​tasks should reliably trigger some cognitive bias or other “glitch.”

  2. Any stepwise thinking needs to be finished within a child’s attention span. Feel free to assume it’s a particularly smart and motivated child if you need to.

I don’t have any kids of my own but have local friends with younger families. Having a few tricks like these really helps me create a “fun uncle” persona, but I’m also curious if parents have a different perspective or experience posing these kinds of questions to their kids.