If you give a boy a vacuum, he will giggle as he knocks all the stuff off the table as he tries to plug it into the wall. As he picks all the stuff back up to put it back onto the table, he will become amused at getting the nativity pieces "reposed" and realize that the wise men can do head stands. All the laughter will attract the attention of his younger brother who joins the laughter and also then stands as look out for "parents".
If you give a boy a vacuum, he will turn it on and then soon begin chasing look-out son around the room with great hilarity. Both boys find this great fun and think that some of the floor must be getting clean so they are accomplishing two tasks at once: fun + assigned task.
If you give a boy a vacuum, he will pull off the hose attachment and see how much suction that "baby" has. Not by actually vacuuming nooks and corners, but by attaching it to his arms and face. Again, this provides a great deal of laughter although it may be tough to explain those little marks on his face.
If you give a boy a vacuum, he will find lots of ways to entertain himself and eventually vacuum the floor.