Reminder: baby termites are cute (even in such a bad pic)!
Their colony (headed by no primary royals but a robust amount of neotenic ones) is maintained in a rather large plastic container filled for 3/4ths with sandy soil; there i buried "bundles" of several 3mm wide spruce wood planks piled one above the other (in my case, 6 3mm planks per bundle), there are two such bundles in the container buried (lightly, leaving just around 2cm of soil above them for ease of future access) in the opposide sides. Though many termites nest in the chamber excavated at the bottom of the container, many others quickly colonized the wood planks, nesting and foraging in them: this setup, beside being highly apreciated by the animals themselves, make their collection very easy as it's enough to carefully dig out a few planks, shake them above a container to make the termites clinging on fall inside, then put them back in their place and re-bury as before. Keep everything always humid but never too damp at a temperature of 24-25C for best result (they can also happily live at your average room temperature year round, they'll just breed and grow slower).
By the way, the species here is Reticulitermes lucifugus, one of the two native subterranean species in Italy. Relatively recently in the north of the country two hotspots of the notorious Reticulitermes flavipes from America (already rather well-enstablished in countries like Spain and France) were identified by authorities. As far as i know, they're not fully eradicated yet, and in all likehood more and more R. flavipes will arrive here from France and Spain.