Put a little note on the invite that addresses the situation. "As we are all young, some acting up can be expected, but aggressive or excessive (humping) furry friends will be asked to leave for the safety and sanity of all. Thank you for understanding" or something to that effect. Most people will accept this because they know what you're talking about. If they are the type of people to be offended at this request, they are probably the people who wouldn't take their aggressive dog home, and their offense will probably keep them home. If anyone calls to ask specifics, or calls you out the day of, remind them that it's your party, and therefore YOUR discretion. You won't be held responsible for any attacks or destruction, so you won't allow that kind of behavior. If you feel the behavior is excessive, they are going home, no questions asked. Most of your friends should understand.
