'Quiet' drinker Beyonce Knowles

Singer Beyonce sits during the 40th Annual NAACP Image Awards at the Shrine auditorium in Los Angeles February 12, 2009. [Agencies]

Beyonce Knowles says she is a boring drunk.

The 'Single Ladies' singer - who is married to rapper Jay Z - enjoys a glass of wine occasionally, but has a tendency to fall asleep if she has too much alcohol.

The 27-year-old star also insists she has never been interested in taking drugs.

Beyonce added: "I always said I would never do it. I've never seen a person who was high and thought, 'Wow, I want to do that!' I'm like, 'That's cool for them, but no thank you. I'll just have my wine.' "

The 'Bootylicious' singer - who has an alter-ego she calls Sasha - often feels people are watching her when she goes to a club to see if she can replicate her high-energy dance routines.

She explained to Britain's Cosmopolitan magazine: "Sometimes I'll dance, but I feel like at a party everyone expects me to be Sasha and go out there and run the dance floor."