They are inveterate devotees of cachaça, the Brazilian 'firewater' distilled from sugar cane pressings. Judging from the leavings to be found along the wall, their favorite brand is "Caninha da Roça," or "Little Cane of the Field," which comes in a squat plastic bottle and costs probably a dollar for a half liter.
Often they are much more closely huddled than in this photo, and sometimes I imagine they are telling cool stories as they squat together in the dirt. But I can't romanticize the passed out, half-naked bodies we often see lying in the shade of this tree or another one just up from it. Grace, when she was first learning about death, would ask if the guys were dead. No, we'd say, they're passed out because they drank too much alcohol.