Unusual worms may be in your garden that you need to know about.  You also need to kill them.  They are land planarian, slimy iridescent flatworms with a hammer heads.  We once thought these creatures to be neutral only eating some beneficials and some pests, but that is wrong.  Rather than helping control termite larvae, grubs and other pests, flatworms seems to be destructive and need to be gotten rid of.  Flatworms only eat earthworms. 

They can stretch out up to 20 inches long and glide along on a layer of mucus secreted from glands along its underside.  These gruesome worms feed by extending their throat out of their mouth and into earthworms.  Small bits of earthworm are swallowed a little at a time.

Land planarians are native to Indo-China, but have been transported to many other parts of the world in the soil of greenhouse plants.  They can survive in freezing climates but don’t do well in dry climates.  They are primarily nocturnal, but can often be found out and about early in the morning especially on wet surfaces.  They can also be found on the trunks of trees. 

Smashing these pests completely is the thing to do.  Be thorough because they grow back from small pieces.  A better solution is to spray them with orange oil to completely destroy and prevent return.