Research scientist Warwick Madden offers up a curious observation about Nasutitermes walkeri.
An observation. Over the years, when I’ve been walking in the bush around Sydney, I’ve occasionally noticed open-topped leads of Nasutitermes walkeri going across the walking tracks.
Instead of tunnelling through the soil, the termites simply build their leads over the top of the ground to get to wherever they are going. Assuming the termites are searching for a new food source (what else do termites look for?) the path appears to be laid down by workers, closely guarded by soldiers.
The leads are sometimes completely enclosed for short distances, but mainly their construction consists only of the sides of the leads, with the top open. With all the human and animal foot traffic along such bush tracks, I assume they would eventually give up and go underground, although I’ve never gone back to check. Potentially, heavier rainfall would also disrupt their traffic.
Recently I observed the same phenomenon in a quiet suburban back lane in Sydney, although in this case they were actually building a lead over a bitumen road! This would seem to have even lower chance of success, with the regular car traffic certain to consistently break the leads. But who knows?
However, there may be method in their madness. Perhaps they build these quick and easy leads using the path of least resistance to explore new food sources. If the food source proves to be sustainable, they then invest energy in building a long term tunnel, in this case, under the road surface.
Whatever the reason, it demonstrates how termites are not always cryptic in their habits.
Warwick Madden, Director, Further Research and Consulting