I have a son overseas but he tries to let us know by email when he's going to call home or he will call, leave a message, then call back in 5 minutes. It's a different phone number everytime so we are not sure what to watch for. He knows how many calls we get during the week. Even Sundays are not safe anymore.
About acting strangely, my oldest brother can laugh like Woody Woodpecker and it really unnerves people! And he has also used that bit about being from Mars. He's a really big guy. One of his nicknames is BigFoot. He can really roll his eyes and laugh his weird laugh and people can't get away fast enough. In other words, he loves to answer the door or phone!
But for us, we let the answering machine get it if we don't recognize the number.