The three year old engineer

You know your small boy (or girl) is going to be an engineer - at least in brain type, if not exact career path, when:

1. He lines up everything neatly.  There are too many examples of this in Nathan's life to count...  But a couple would be the lining up of any vehicles he's playing with, and his playing of the memory game: All cards must be the same way up, even if it's just the pictures on the reverse of the cards, and they must be placed in neat lines...  Heaven help us if anyone introduces him to a set-square!
2. When drinking from a glass, he has to position it so the writing (IKEA!) is horizontal... 
3. When playing with a car with motorised wheels, he picks it up, just to turn it upside down and watch the wheels going round.
4. His vehicle noises are convincing enough to get you to look in the sky to see the aeroplane that isn't actually there.
5. His three favourite things are a torch, a screwdriver and a tape measure (metal and retractable, of course...)
6. He has an inbuilt fascination with how things work...  The trigger for this post was a few incidents I had with Nathan emerging from the bathroom with a wet sleeve...  It was wet with water, nothing more unpleasant, but more wet than would have been caused by an over enthusiastic hand washing.  I found out the cause of this by spying on him...  Let's just say that toilet cisterns are plenty wet enough, and also very interesting to a certain type of brain...