Recently, there are flying insects in my room, which look like ants. Sting hurts, and a small bag will come up. I don't know what an insect is and how to kill it.

It's ants. Now it's time for the ants to divide their nests. Some kinds of ants grow wings when they are sexually mature and fly out of their original nests. When you find the other half and the right place to nest, you can fold your wings and settle down. Since then, a new ant nest has been born. If you haven't found the other half by then, God will say goodbye to him. It can be killed by spraying pesticides such as "miehuling" sold in the market.