You're making her a little nervous. And she probably likes you.
(Either that, or she doesn't know you're alive, her thumbnail is bugging her, and she's biting it off.)
If they aren't hissing as they do this, they are just trying to play with you or trying to get attention. They could be bored.
He's hungry
You have startled the dog..scared him
I think they're just hungry...
A ant that bites a human that turns the human to a zombie
Biting his lip could be a sign of nervousness, attraction, or anticipation. It can be a subconscious gesture indicating that he is feeling self-conscious or sexually interested in the girl he is talking to.
They like you
She's either concentrating, is nervous, or is teasing you.
it depends.. It could mean shyness or boredom or it could just be a habit ;)
i think they're mating
Doing nothing -- Standing around with your thumb up your nose.
He's just really horny at the time and wants to fool around with you.
it means that the girl wants you and you should embrace that and hug her around her waist and make her feel good because it is most likely the girl does not acctually feel that way unless she has told you or hinted to you or others before.
It probably means that your female (girl) Betta is a male that has not yet fully matured.
he wants to kiss you ;* no joke, I really think so...but I'm a girl (: And if he bites his lip, that's a plus! go get 'em girl! ;D bahaha
what does the phrase rule of thumb mean
It means she likes you! Any other detailed answer?