A.H.
is it the dad too making a mess? find out... also if it's the boys.. show them the mess.. tell them that they will have to clean it up if it continues. the day I started my son (at age 2) going to the bathroom.. I showed him where to aim.. and not to get any on the wall or floor.. to this day.. at age 13.. he hasn't missed yet. My husband is also neat when it comes to using the toilet. Give them a wet wipe after they use the bathroom and show them how to clean it up.. they won't be happy and I'm sure they will improve after having to clean up..good luck..