hawkfly

here is a closeup of the tails - they are much more delicate than the responses

have never used leech yarn but these tails seem too delicate and they have some type of flash worked into them

thanks so much for the answers. I will get started. Assuming practice will let me get a more delicate result

i think these are bead head leech paterns. they are tied in small sizes i use them with great success for smallmouth in lakes fished deep. My question is are the tails made from dubbing loops? They are so thin/delicate and never unravel even when fished extensively. Thanks in advance for any help.