The maximum rate of inheritance tax in Japan is 70 percent, more than many people can afford to pay: If they inherit, they have to sell off land and property to pay the tax.
Researchers at Toyama University have discovered a similarly high cost to inheritance in an ant species. Kazuki Tsuji and co-workers at Toyama University studied an ant common all over the main Japanese islands, Lasius japonicus. In this species, a single queen presides over a colony of around 10,000 worker ants.
The nest is a complex structure that many thousands of ants have cooperated to build, and as such, like a family house in Tokyo, an established ant nest is a valuable structure. All the workers in the colony are female -- all sisters -- but they are sterile. Only the queen lays eggs.