New piggies!

[Honey15000]

Hello! I'm new! I have two little boy piggies, I got them today from the pet shop! Norman seems a bit more confident and has been out exploring, although jumps and runs a mile if one of us move, Kevin is a bit more subdued at the moment he hasn't really come out the igloo! Earlier after being in the cage together for an hour they both went into the igloo and seemed to have a bit of a tussle , then came out into the cage and did the same thing...sort of nose banging and teeth clashing but they have settled....but Kevin is quieter....is this them just testing the waters and trying to determine who is the most dominant, they lived together but with others in the pet shop!
I have a wooden thing that ive folded into a tunnel so they both have separate hiding places! Also Normal has been making a purring/ bubbling sort of noise...is this a happy noise?
Thank you in advance! X