Today, Higashi estimates, it has reduced the number of ants living there by more than half. Maybe then we could have done something to save it. The Japanese wood ant defends itself easily. Touch the outside of one of their mounds, and ants will rush up your arm and deliver a smarting bite. But it is extremely sensitive to change.
Vibrations caused by jackhammers and trucks can easily wipe out entire nests.
Roads, waterways and buildings can restrict the ants' ability to move between the nests of the colony. Still, the Hokkaido government and authorities in Tokyo say protecting the colony is not of particular concern. There's nothing we can do. So the construction continues. Higashi rarely gets out to see his ants anymore.