Have you ever wondered what the difference between a regular insest and a pest is? It is something that the Pest Control Essex based company https://www.bpcpestcontrol.co.uk/ has to answer on a daily basis. The first thing they will tell you is that insects have been around a lot longer than human beings have. When Dinosaurs walked the Earth there were insects buzzing around annoying them just as they do us now. However, it should be remembered that insects play a vital part in our world’s ecosystem.
Basically it all comes down to behaviour. Not that you can tell a flea to behave itself. It provides less of a useful purpose than other insects do. For the most part insects provide a food source for birds and small animals. When it comes to spiders and flies they occasionally seem to make a tasty snack for Cats. One of the best and well known insects that is not a pest is Bees. These helpful creatures pollinate plants as they collect it for their hives. Without them we would be in serious trouble as plants would not grow.
The real definition depends on whether the insects are causing you trouble. If they are in the home and biting or causing allergic reactions then they are really defined as a pest and will need to be removed. The basic definition would be a small yet destructive presence that has an adverse reaction to the lifestyle of the humans in the home.