"Received a gift from a dear friend, the Carmen Amaryllis In A Red Pot, just before Christmas. The next day we started having large blackish flies in the house. Never had seen this type of fly indoors before. Every day for the next four days, we would kill from four to six flies every day. The common flies we see indoors in southeast Texas lay eggs in rotting animals but we didn't smell that distinctive odor. Finally, I took a photo using the app "Picture Insect" - it was a "Stable Fly", which lays its eggs in putrefying organic materials such as moss, mulch, etc. The exact same medium in the "Red Pot". Don't open nor keep it indoors."