Why are my nails see through?

Just wondering why they’re doing this? I’m usually a nail biter. So this is kind of ‘long’ for me. Sometimes I’ve gotten them longer by using gel/shellac. But this time I haven’t been putting anything on them but there are certain spots that are see through. 🤷🏻‍♀️🤷🏻‍♀️🤷🏻‍♀️😑 does anyone else’s nails do this?