hey

hard to tell w/o a pic ...

but if the green is attached to the brown inside.. one might suggest you dont go trimming it all out ...

most trees and conifers are barren on the interior .. and that is normal.. so you can see our conundrum on how to advise w/o pic ..

that said.. if these are your standard monsters .. which were once cute little plants.. planted a foot or two from the house.. then most likely.. its time for them to go ...

ants dont nest in trees .. so i am confused by that...

but my bottom line usually comes down to the fact that this is .. presumably .. the front of your new house.. and you should not do long term renovations out front.. and you should get rid of the prior owners mistakes.. and start afresh ...

a pic MIGHT change my mind..

ken

Just for completeness' sake, carpenter ants do some tree nesting. Not at all to say that's what OP is observing though.

And yes, interior brown stuff is normal in most conifer species, especially prevalent now that fall is near. As far as "keep watering", do they need water? Is the soil dry-drier than is typical for this time of year-in your area? If these are full-grown, and junipers fordachrisake, I'd not think they'd need supplemental watering.

More info please.........+oM