this is a funny thread for reading about those 'tendencies':

The Destroyer

Yes, I would say it is "normal". Normal for kids whose parents are posting to this forum, anyway. smile

The microwave, as my husband has many times described to me, works by agitating the water molecules in anything. With little water, there might be little heat (but lots of sparks!)

Here's some actual info, yay! Turns out it's not just water.
http://wiki.answers.com/Q/How_does_the_microwave_oven_work

https://twitter.com/asimom, https://contributingfactor.wordpress.com