When my cats are home alone, if someone drives up and opens their car door, they get inside. They also leap into moving strollers (with babies inside). Who knows what theyd do if someone came to the door (sigh)
Children's Bed - Looks Like A Little House Headboard . instructions seem to be in Dutch, you can try translating it into English but you get the idea for a cute bed that you could copy from the picture and the dimensions of a twin size bed.