new boa owner seeks advice.....

[Gemin][][]

I read the post by Hollywoodsnake about her being afraid of the snake she was snakesitting . Now I just inherited a columbian boa from a friend who claimed to not to have time for it so I said ok kool.I fugure all i need to do is just to get to know the snake a little better and to get to know its habits, but the kinda thing freaks me out some times,plus I've got kids ...lol... but they love it.He said the boa loves the water, so I figured I would give it treat and bathe it, but it swims around and tries to get up the side of the tub, cant; then opens it's mouth. Is it pissed off or natural....?I expect to get bitten one day but not this soon you know.I want to take all the nessacary steps to have a healthy snake.I think it was underfed and you can see its ribs and I was told that also, I want to get it bigger so im feeding it like 5 live mice a week he is
2 1/2 to 3 years and 4 feet . I handle him a fair bit and feel comfortable doing it but one time I took him into public he was great, but after a few hrs he opens his mouth too.... I just wanna learn as much as I can, but the net only offers so much....ty and look forward to responses.