Yes, i like ytong nests too, cheap and easy to make. Also Camponotus herculeanus are very slow to develope so if you plan on keeping them you will need lots of patience.
thanks guys yeah i all ready have Camponotus ligniperda and have now got used to slow growing ants. is cork good as well because i was planing in putting a peice of cork in a 3Ox2Ox2O basin up against the glass. as i know they like wood