Coral Snakes don't drop anything?

I have attacked a number of groups of coral snakes also and gotten nothing.

Also I hit an elemental who was stood on some salts last night, he not only did not drop any himself, but he took out the other salts too, very annoying.

On a side note about 2 days back I hit 2 groups of Many Elephants... and guess what?.....  Did they drop something?.... OH YES...... each group dropped puma fur !?!?

I don't know anything about coral snakes, but sometimes elementals don't drop any salts.  I haven't been able to figure out much of a pattern behind this, other than usually the more elementals you kill the more likely you will get at least some salts.