First of all, you may have been under great pressure (including emotions) in your life and study recently, almost to the limit. I hope you can find out the reason carefully and adjust it in time.
Of course, recently, someone has made you upset, angry and unhappy, so this kind of thing appears in your dream, and even you will feel very anxious and helpless in your dream. Beware of villains and pay attention to traffic safety when traveling.
I usually have this dream when I am in a bad mood or too tired, and I feel the same way. Don't take it to heart, be careful in everything and be patient with others.
Spiders in dreams generally represent villains. Mantis and flies have no special meaning. Ignore them.
The most important thing is that they all died in their dreams, which means that the unhappiness and threats in reality have been lifted. You can live a normal life with peace of mind and sincerely wish you, my friend.