I've been tying flies for years but only recently decided to tie some bead head nymphs (don't ask me why I waited so long - I think I am too much of a traditionalist) I hope I'm not duplicating questions but I can't find answers using the search or in the beg/int tying sections. So, here goes:

1st dumb question: When you tie a bead head do you use a larger size hook than you normally would to match a specific insect? For example if I would normally use a size 14 hook should I use a size 12 (or 10) to compensate for the size of the bead that isn't really part of the imitation?

2nd question, probably dumber: My beads have a large hole on one end and small hole on the other end. Which end goes closest to the eye of the hook? When I put the small end closer to the eye, which seems more natural, the bead has a tendency to move back over the body of the fly. When I put the large hole towards the eye I don't have this problem but it just doesn't seem 'right'. How do you prevent the bead from moving around on the hook?

Thanks in advance for your help.