Note to Nancy! I am curious as to what sort of comments you are getting from your son's preschool teacher, and in what situations. If you care to and have a minute, let us know! That goes for anybody else who has something to add too!
Re: "Disruptive" behavior: I wish I had written more down when my son was young! THANK GOD my natural rebelliousness kicked in and I never considered putting him on hyperactivity drugs. My son grew out of the "bouncy" period and I have much more experience now with things "boy". (I only have sisters and female cousins, so a boy was really new to me.) After observing my friends' boys, my son's friends etc., I have to say that my son was absolutely normal, if not on the tame side.
Little boys bite, climb, enter a room like they are storming the Alamo and seem to love to grab anything within reach. They view furniture as an indoor jungle gym and would rather climb over a sofa than sit on it, or better yet, climb up on the back of the sofa and then jump off as many times as they can get away with. Some friends of ours have a 5 year old boy who always climbs our stairs on the outside of the railing. He also bites his big sister (for which he received Cayenne on the tongue, which has discouraged further incidents). Running while making loud noises seems to be a big hit as well. My own son went through a six month bout of that, during which time he insisted on wearing his "Batman" costume to pre-school every day.
He would also put on several layers of clothing underneath. I was helpless. He insisted on Batman and would put up such a fight that in the end I just let him be Batman and said to myself, "OK, so my kid's a bit weird". I mean first off, can you imagine going to school wearing the same outfit twice in a row? The other kids thought it was cool, though, and since then I have heard similar stories from other moms (Superhero can vary, however.)
In the end they sort of grow out of it by themselves (with the proper guidance) and become very interesting young people. It never ceases to amaze me though, how differently they view things than girls. I was a bit of a Tom Boy when I was a kid and yet I never came close!
But back to all that hyperactivity...It has also occurred to me that parents seem to be hell bent on having their children learn to read as early as possible, and as a whole we seem to be shoving the 3 Rs at kids earlier and earlier. Book learning is not something that is easily done while climbing a tree, in fact I would strongly advise against it. Book learning requires you to sit still and focus, which girls are better at in the younger years. So boys will naturally come out of it looking like the troublemakers who are preventing the teachers from giving the overeager parents what they want! (The ability to brag to their friends that Johnny and Janie could read when they were 16 months old.) In the end, it doesn't make a lick of difference in the overall scheme of things whether you learn to read, write and 'rithmatic at 3 or 4 or 6. Really...It doesn't. Send the poor kids out to play!
And PLEASE let the boys be boys!