In my experience, just about every living creature fills a niche in the circle of life. Even some mof those I despise mose like flies, who help dispose of dead things and are also eaten, and moquitos, who are eaten by other creatures.
But fleas… what do fleas DO except make other animals miserable? They are not a diet staple that I am aware of, they don’t act as a clean up crew, they just… are. Can anyone come up with a good explanation why every flea on the face of the planet should not die???
(Yeah… I hate fleas with the passion & heat of a thousand imploding suns.)
Fleas are pretty good at being and keeping alive - they reproduce ridiculously fast, pitch their tents right on top of their meal ticket (which will then do all of the busy work and can sustain the hunger of, like, a billion fleas at a time) and they have zero predators or other cause of unnatural death that I’m aware of aside from the dreaded B-A-T-H.
They’re very close to the ideal, perfect life form. Right next to cockroaches, naturally.
In fact, dogs only exist for the purpose of providing a substrate for fleas, and humans only exist to take care of the dogs while they do this. The OP has been greatly misinformed about the purpose of the ecosystem.
Some parasitic nematodes kill fleas in order to reproduce, and anything small enough (frogs, lizards, spiders, etc.) will eat fleas if they get a chance.
I think when over crowding occurs fleas may contribute to slowing down growth of a species. Overkill to the max as they might only make things miserable for a century at a time before they get the opportunity to really do some useful killing.
Another view is they are still finding their place in that great cycle. We live in symbiotic harmony with many organisms that exist inside us. They and us have found it mutually beneficial and we evolved to allow this co-existence to the betterment of both. In the case of the flee, or other parasite there is a ongoing evolutionary war going on, slow but on going, as the host gets better with dealing and possibly eradicating it from it’s species, and predators may evolve to also counter it. Evolution also gave rise to technology which is another way to battle these parasites. So it’s purpose, as you are asking, may not be yet realized but lies in the natural evolution process, our ability to stop/hinder their parasitism using technology and their ability to evolve to something that has beneficial qualities.
So unless/until the flee starts being some sort of benefit and stops just taking from others, it will always be a much despised member of the kingdom.
