So I've had my boa a couple months now and have had no problems with her, recently however I've noticed small flies in her tub, she's in an 84 litre box with lots of holes for ventilation as the humidity was too high without them. I keep her on orchid bark and I was wondering if its possible the substrate had them in when I bought it, I'm not certain this is the cause as I had a similar problem with my Giant African Land Snails and they were kept on compost. I thought they may be getting into the tub but its winter now and there are no flies about and I never find any flies in my corn's tub which is right next to the boa's and also has lots of holes for ventilation. When I first noticed the flies I cleaned the tub and put in fresh substrate but within a few days they were back. I was wondering if anyone has had a similar problem and if they did how they dealt with it. It doesn't seem to be affecting the boa at all as she is still eating, shedding, etc fine and doesn't seem stressed at all but they're just annoying me to be honest and I want to get rid of them. Thanks in advance for any help or advice