Paramites sense the world primarily by smell. I believe Scrabs sense the world, at least the inhabitants of it, by electroreception. As for
why there are so many, I can see two likely reasons.
- No eyes is easier to animate than yes eyes.
- Lorne loves and is fascinated by animals that deviate from our expectations of life, hence also the heavy use of so-called 'super species' as a reproductive method.