From Sahih Bukhari (Hadith 6296):
Narrated Jabir:Allah's Apostle said, "When you intend going to bed at night, put out the lights, close the doors, tie the mouths of the water skins, and cover your food and drinks." Hamrnam said, "I think he (the other narrator) added, 'even with piece of wood across the utensil
Reference: Bukhari 6296