What do Dragonflies do to the environment?

Question

What kind of stuff they eat or what. Do they attract birds or wasps or anything?

Answer 1

They eat smaller insects.  We have lots of them around here and one day I saw a group of small birds flying around and catching and eating them.  We also have a lot of wasps but they and the dragonflies seem to ignore each other.  My little chihuahua likes to try and catch the dragonflies but they're too fast for her.

Answer 2

Dragonflies eat mosquito 's  an other small insects.