Stealing food

Question
My 9 year old beagle is constantly on the hunt for food.  She is
very agressive and takes food right out of people's hands or
mouths.  In addition, she takes any change to escape the house
to scan the alley for garbage.  She even got into our neighbor's
car and started eating the groceries.  For family mealtime. she is
gated in the room next to us and does OK. The problem is when
we entertain.  We gate her in the kitchen and whether the party
is inside or outside she bays the entire time (for hours!)  We give
her a bone with peanut butter smeared on it and that only gives
us 10 minutes at the most. It is very stressful to have anyone
over to our home.

Answer
How much do you feed her? Some beagles seem to have a bottomless stomach.
First, she shouldn't be able to escape the house. Make her sit at the door and wait for you to go outside and tell her come on. If she tries to sneak past you put a lead on him and step on it until he sits and waits to go outside.
Make her sit before she can get anything to eat. When you give her a treat turn your hand inward so that she has to turn her head to get it.
Teach her how to bark. Have you taught her how to speak? All dogs bark or bay in our case. Make her howl. Then, tell her "Quite" and give her a treat and walk away. Do this so she learns what "quite" means. When you have company put her in the kitchen and tell her quite. Also, get a hollow fake bone with the pet store and fill it with peanut butter. Turn a radio on in the kitchen. After she has learned this you can have a friend or neighbor come over to help you practice before your next party or dinner.
Is it possible to have her outside with you guys when you are having a party? If you can, you can tether her to a tree or stake. She would like to be outside with you and people will be able to go pet her but, the non-dog fans will not be bothered. If she is howling outside or inside you can spray her with a spray bottle filled with water and tell her "quite" then walk away.

Fellow beagle lover,

Kenny