Alan,
If you prefer, you may stalk them. Of course, lurking in alleys wearing a long raincoat and slouch hat is a good way to get a bad reputation, as a stalker.

Well-trained congo hounds don't actually attack the quarry. They frighten it so badly that its hair falls out. Then the hunters are able to collect it in sacks. That's why the base color is white and why it can be found in such lengths. Please note that the yellow hair is left in the field and any yellow congo hair which you buy was dyed after it has been collected. That is another reason to always buy congo hair from reputable vendors, and not the sorts who stand around in darkened alleyways wearing slouch hats and raincoats.

Regards,
Ed