Small fly (likely fruit fly)

Common around ripening or fermenting fruit, sugary drinks, food waste, drains, and other moist indoor sites.

Adults feed on yeasts, microbes, and sugary liquids; larvae consume fermenting organic material, especially fruit and beverage residue.

They are attracted to fermentation odors and may enter through tiny openings, including drink lids. Females lay eggs on moist food residues, and development can be rapid in warm conditions.

Usually harmless and do not bite, though they can contaminate food with microbes. They help decompose organic matter and are important research organisms.