What is the Christmas tradition mumming and what do mummers do?

I believe they do it in Newfoundland, but it originated in Ireland/Britain. Around the holidays men dress up like women and women dress up like men, go around to houses and have a drink and a laugh. Ask a Newfoundlander for a more detailed answer/and a reason.

EDIT>_< I, sir , am a 14 year old newfoundlander. THIS is the answer your looking for:

Im doing homework on it now and i found this so i thought id help chu out.

Mummers also called 'Jannies', have been a tradition in Newfoundland since colonists from England brought the custom at the beginning of the seventeenth century. Sometime during the twelve days of Christmas. People would disguise themselves with old articles of clothing and visit the homes of their friends and neighbours. They would even cover their faces with a hood, scarf, mask or pillowcase in order to hide his/her identity. Men would sometimes dress as women and women as men. They would go from house to house. They usually carried their own Musical Instruments to play, such as fiddles, sing and dance in every house they visited. The host and hostess would serve a small lunch of Christmas cake with a glass of syrup or blueberry or dogberry wine. All mummers usually drink a Christmas "grog" before they leave each house. (A grog is a drink of an alcoholic beverage such as rum or whiskey.)

The would also play a guessing game in which the host of the house and his guests/family would attempt to figure out who each mummer was. If a mummer's true identity was discovered then he/she would have to take of his/her mask. For a time the mummering tradition started to fade in the more urban parts of Newfoundland but was revived by the famous mummering song by Simani.