Nagano Prefecture applies a de-icing compound to its roads to prevent them from freezing over in winter, but the substance may be endangering wild deer by luring them to busy routes to feed on the salt it contains.

"The compound is an easily accessible source of salt for deer, and more of them are wandering onto roads to lap it up," said Manabu Miyazaki, 62, who has photographed such behavior.

The de-icing compound, which is made from sodium chloride or calcium chloride and other chemicals, has been in use nationwide since the 1980s.