HELP, I have a few thousand tiny black looking microscopic flies on my ceiling and curtains. They came in when?

You can drown them in any kind of spray. Spray starch,hairpspray, even liquid dish soap watered down in a sprayer. I buy Method brand natural spray cleaner at Target which i would use in this case. Good luck! (I doubt if they are fleas,they don't stay still very long,they would be jumping on YOU!. )

Flies truthfully see the wrong way up, so it is in general so much simpler to land the wrong way up than it's correct facet up. They simply do some L curve touchdown without doubt. Image if a aircraft had been the wrong way up and needed to land.. It's kind of like that.