They're not much of a threat on their own (if you have decent enough armor and food)... but they can become a trouble when they pair with berserker or lox... cause if you miss the first hit, then you don't really know when it hist again. Sure, the pattern is simple and if its alone you can counter it very easily, but when you're busy running around berserker or lox, it can become hard to also avoid this little buggers.

That's why, ALWAYS clear the area off of them before you go into major battle with big guys.