Two queries, Please Help!

[Bearybearington]

Hello, brand new member here. Been lurking and reading lots all year though..

So I have two questions id love to get anwsered, one is more important than the other so feel free to just anwser that..

1. Are Ants in my blue tongue skinks enclosure an issue to my skink? There are no dangerous ants as far as I know in my country (Nz) but im worried the ants are a sign of low cleanliness or similar?? I think the ants have come in maybe on substrate/rocks (rocks were washed but not baked and substrate is store brought). I had been trying to house/farm Isopods to have a clean up crew but they keep dying and arent sold as pets etc here either

2. This is more curiousity then anything, is a red colored belly a sign of anything with blue tongues? See I have 2 eastern blue tongues (only kind in nz as far as I know) and dont know genders of them. So one of them has a red colored belly (is the more active moving one) and the other slink has a white belly (this skink is my lazy one).
Ill edit with some photos hopefully in a few hours after work

[splashy07]

The red belly thing is common, three of my easterns have it. As far as the ants, personally I wouldn't want them. Just don't like them and they could infiltrate your living area as many types of ants can quickly colonize in a domicile.
You may be having issues with isopods as most require a damp environment, there are some types that can tolerate drier conditions.