Usually 30mmm x 200mm so they can house large ants
With a refillable sand hydration chamber at the back.
There is a member here called Leo that uses one for his ants
Pics from Leo's journal
https://lh6.googleus...-F7A=w1920-h912
https://lh5.googleus...JJEA=w1920-h912
https://lh6.googleus...XUj0=w1920-h912
https://lh4.googleus...HUEv=w1920-h912
Easiest place to buy them from is Aliexpress, it's kinda like a Chinese Amazon. Pretty safe, I've bought a few things from there.
You can see them listed here. They come in various colours and combinations, some as part of a large acrylic formicarium with 1-10 of these tubes as well.
https://www.aliexpre...bamboo ant nest
http://img.alicdn.com/imgextra/i2/3340958150/TB257IWvMxlpuFjSszgXXcJdpXa_!!3340958150.jpg http://img.alicdn.com/imgextra/i1/3340958150/TB2QoJrvYVkpuFjSspcXXbSMVXa_!!3340958150.jpg
http://img.alicdn.com/imgextra/i3/3340958150/TB2Lo0rvYVkpuFjSspcXXbSMVXa_!!3340958150.jpg http://img.alicdn.com/imgextra/i4/3340958150/TB2A2SFXtqgF1Jjy1zdXXc8dFXa_!!3340958150.jpg
http://img.alicdn.com/imgextra/i4/3340958150/TB2jIkoXfAPyuJjy0FcXXbCzpXa_!!3340958150.jpg
Edited by CoolColJ, March 16 2018 - 4:08 PM.