Hi, Maggie, They're simply fun (hopefully) ways to catalog people's activity level on the site. You amass points on the site for doing various things - like uploading clips, writing blog posts, etc. And as you amass points, you graduate from nibbler to gnosher to gobbler. (My platform host, Hoop.la, has set the algorithm that determines which activities on the site get the most points; even I don't know it. But I've set the point levels at which one moves from nibbler to gnosher, and so on).
If you go to your profile and click on "Activity Level" to the right of your name (see first attachment), a window will open up (second attachment) that shows the points needed to advance from one level to the next. Your accumulated points also appear at the top right of your profile.
Again, this is simply intended to be a fun metric to watch - nothing at all competitive. If you don't want it to reveal, then go into your member profile and edit your title. If you enter a title, your activity level will not reveal.
P.S. I am moving this question into the "Site Stuff" forum because I think it better relates to questions about the site than casual cookie chat, and more people are likely to find it there. It's a good question, so I don't want it to be missed!
