Now days people just don’t get it that kids are not welcome all the time.
I mean, we love ours but we would never just assume they were invited to a party unless it was indicated in the invitation.
If you address it to "The Bear Family" or you list the kids by name then we assume they are welcome. If you address it to Mr and Mrs Bear or Harmless plus one then we will be getting a sitter.
Same with dogs in restaurants.