Dogs are a lot like children--they can get very excited when visitors come to your house--and it can be common for the "house rules" to go right out the window in the excitement. Don't let your visitors encourage your dogs to behave badly. Here are some tips to help make sure that your pet follows the same rules when guests are visiting as they would any other time.
Guests and food
If your guests are constantly trying to sneak your pet treats when they visit, you will probably find that this encourages your dog to beg for food at other times. This really isn't your pet's fault--he's being sent mixed messages and will go with whatever gets him food and praise.
Make it clear that your pet may only be fed appropriate food at appropriate times. If your guests want to give your dog a treat, make sure it's a dog treat, not a bite of food from their plate.
Guests with small children
Small children can be very excitable, noisy, and rough. This can make your dog feel insecure and even threatened, which could result in biting or other unwanted aggressive behaviour from your pet.
Again, this isn't your pet's fault. When a child is loud or rough with your dog, your dog could feel threatened or scared. Make sure you correct the child's behaviour--not your dog's--to keep order in your home.
Make sure your dog has a safe place to retreat to when kids are around.
Guests with other dogs
Doggie playdates are good, but if your guest's dog isn't housebroken, it could cause your dog to behave badly. Another dog's "accident" inside your home isn't just an inconvenience to you, it's a sign of territorial marking to your dog. When your dog smells the urine of another dog, he will automatically want to cover it with his own scent.
Unless you want your dog peeing inside your home, make it clear that untrained pups have to stay outside or at their own home. Your dog is only going to do what nature intended and mark his territory if he feels that he's being "invaded" by another dog, so save yourself a lot of trouble and limit your visits to outdoor ones.