The other nine trackable hunter pets in Pandaria walk in predictable paths leaving footprints that eventually lead us to the beast making them. Originally all of their tracks were backwards, several have since been fixed when patch 5.1 went live. These beasts are completely stealthed, and the only thing that will make them visible is for them to walk through a flare. A Hunter's Mark placed on the beast will keep it visible to the hunter that placed the mark until the flare wears off.
Like the other nine beasts, Bombyx is stealthed and leaves tracks that can only be seen by hunters. His tracks however are unlike anything we've seen so far. He doesn't leave actual footprints as tracks, he instead leaves a trail of Heavily-Chewed Silkweed (pictured on the right in the screenshot below.) Unfortunately because these "tracks" are basically a small tuft of flowers (and look just like a smaller version of the Silkweed herb), they do not point in a particular direction. This makes determining the direction that Bombyx is travelling incredibly difficult.
As if not knowing which direction he were moving weren't difficult enough, he also moves VERY sporadically. He twists and turns, doubles back repeatedly and even stops in place for lengthy periods of time. In the screenshot below you can see there are Heavily-Chewed Silkweed tracks all over the place. Where does one even start looking for this guy?!
Well, I can't give you a precise map like I did with the other nine pets, but I can point you in the right direction. You should begin your search for Heavily-Chewed Silkweed within the small purple circle that I marked on the map below. I watched Bombyx for quite a while, and he never left this area in the time I spent watching him.
|Click map to Enlarge|
If your having trouble locking down exactly where he is, I would advise tossing a flair at that location and waiting patiently for his return.
I've got a video below that shows this particular spot right at the beginning. After I tame him in the video, it continues on for a few minutes just watching where Bombyx walks. Hopefully this gives you an idea as to just how sneaky this squirmy wormy is.