I haven't had them kill them selves whilst running into the starter block when it was just sitting there.
Nor have they been killed from friendly fire.
They have however, been killed when the knock the block forward 'squashing' others, or a shot (friendly fire) and knock the block forward killing themselves. No damage is taken from the friendly fire itself, on the act of the block moving and hitting them.
You able to supply more information on what you see? Screenshots perhaps?
Mobs in Minecraft had the ai for awhile were they would determine if they could survive a fall enough to still get to you. Before that, they would jump off any height to attempt an attack. The AI will improve with time.
Hmm alright... well I'll add this to my compilation of threads... but I'll probably just put it as not a bug... just because I'm not sure as to wether it's just silly AI/blocks jumping around or what ever... If you suggest otherwise I'll take that into account
Yeah... it does seem like their health is a little low, but it probably allows the user to easily kill sheep (by just running them over with wheels). It would be an interesting balance between more health and less health (or amount of damage given by things, the falling damage could probably be lowered)