I agree as well. Plus, eye contact with them continues to engage them in the conversation. If they are starting to drift off in their thoughts, when you engage them with contact, it helps bring them back into the conversation.
Teaching online, my best option for engaging is to actively ask them individually questions as I go along, or to ask them all a question and for those who don't respond, ask "what about you... so and so...".
In the classroom though, making sure to touch in with each student with eye contact and trying to smile helps keep them… >>>