Hammerhead Worm

After a rainy day yesterday, the mountain trails were still wet this morning. With few people out hiking (I saw only one other hiker), it was a great opportunity to observer nature (such as spiderwebs in the face). I saw a very large snail as well as a hammerhead worm today.

I see hammerhead worms in the mountains often, usually when the ground is wet. The ones I see tend to be around 30cm long and pure black. They are called コウガイビル（笄蛭） in Japanese. ヒル（蛭） is Japanese for leech, but it is a misnomer, as a hammerhead worm is not a leech (different phylum).

Leeches are pretty common on some hiking trails in Japan, but (thankfully) not on the trails that I hike most often. In Japan, one often hears that it is best to remove leeches using salt. This is not great advice, as a surprised leech can vomit blood back into your wound along with bacteria, which can give you an infection. It is safer to quickly remove a leech manually (using a credit card to break the suction, for example) or to simply wait until it is done feeding.