My 18 month old son was w/ his dad in lake cabin one month ago overnight. i just found out they slept with the balcony door open as well as the windows. his dad said they didnt see bats but didnt look either concerned about son being exposed?

Not a problem: If your child is not ill you should have no concern. There is generally no real concern for exposure to bats in the wild in the US in relation to the corona virus. We generally do not have the close contact with animals that often occurs in some of the Chinese markets. It is only a hypothesis that the virus might have originally been contracted from overly familiar contact with an infected bat.