This makes the kids excitable, and hard to manage. However, enthusiasm is a must. Watch any excellent teacher. Good instruction requires good pacing - not too fast, and not too slow. The teacher may stop, abruptly, at any time, if a student begins to visit or disrupt.
Good teachers use proximity well.
Seats are assigned so that potential disruptors are near the front, talkative pairs are split up, and the teacher can easily walk, in an easy, deliberate way, toward those who are talking or inattentive. Do not neglect the outer fringes. Walk and gesture, easily, calmly, naturally, as you talk. If you use a board or overhead, move away from it when you are not writing, and look at the kids, one by one, as you speak.