春先から夏の終わり頃まで、地獄の歩道ではいくつかの昆虫と出会います。
　その1つが体長3センチほどの「ハンミョウ」です。背中の光沢が美しく目をひく一方、鋭い牙で蟻やミミズを捕えて食べるという肉食的な性格をもっています。
　ハンミョウは別名「ミチオシエ」とも呼ばれ、人が近づくと、2〜3ｍ先へ何度も道を教えるように飛んで行きます。
　その他、この地獄で一年中見られるのが「カマドコオロギ」です。地下から上がる地熱によって地表が暖かく、一年中、成虫と幼虫が見られます。雪が降り積る真冬でも、ちりちりと鳴く声を聞くこともあり、まさに雲仙地獄特有の生態系といえます。
また、初夏から秋にかけて、渡りの蝶として有名な、アサギマダラを地獄歩道周辺でも観察することができます。

★ 英語バージョン
　From late spring to summer, a variety of insects can be seen along the paths through the jigoku. One is the hanmyō, or Japanese tiger beetle (Cicindela japconica). The largest tiger beetle in the Japanese archipelago at approximately 20 millimeters in length, the beetle has a glossy shell and sharp pincers, which it uses to eat ants and earthworms. The tiger beetle’s somewhat erratic behavior has earned it the secondary name of michioshie, meaning “guide.” If you walk close to it, the beetle will jump two or three meters ahead. If you follow, it will leap forward again and again, as if helpfully leading you down the path.

　There are many more insects that call Unzen home, such as the maritime earwig, or the tropical house cricket, which can be heard chirping at night. If you look, you are likely to find other beetles, moths, butterflies, and more. If you don’t get a chance to see these insects in the wild, pay a visit to the Mt. Unzen Visitor Center for a close look at their preserved specimens.