Forum:The grox Expanding

I wanted to ask a question about the grox because I am thinking about starting destroying their planets but I always wondered:do they take back the planets you captured or destroyed(obviously if i terraform then then no but this is really time consuming i want only to destroy the base then leave)?And if they attack one of my planets or my ally do they take it over or just destroy its bases?Because if i start a war and then have to run all the way back to save one T0 planet every 5 min i will go crazy....(and again i do not want to terraform every planet i have:))