Oh Lord, I love reading
internet experts.
They might be bees. If they are, then they are apis melifera, the honeybee. This is highly unlikely since bees like forest. But God knows, I've seen it all.
Or are the hornet "bees"? Hornets will nest anywhere. They too build a nest that can encapsulate halyards. Sans the honey, which is immaterial.
The elimination of either is similar- destroy the nest. Your halyards WILL move, which will break up the nest. Noting, of course, that it's not unlikely they chewed through the halyards which were in the way- but you'll figure that out when it drops to the
deck.
If they are honeybees and you want the $30 queen, drop the mast, cut into sections on either side of the nest, and extract the queen. If you don't want to cut up your mast, the forget the useless
advice given elsewhere.
Tie off the
head of your halyards (I shouldn't have to say that) and then yank them back and forth to destroy the nest. Do this at night, since bees and wasps sleep at night. I'd do it during the day, but I've been stung over 4000 times, so your preference may differ. Bust up the nest. It may have to be a repeated (almost daily) event to make it inconvenient for them and convince them to leave. Forget the poisons and such, if they're mid-way it will only piss them off and not kill the nest.
The real problem you may face (particularly with hornets) is that they may have removed some of the protective plastic cover on the wire/ coax. You'll figure that out over time when lights, radios, and such don't
work quite right.
My guess is that they are Vespa maculata, the bald faced hornet. Second guess, yellow jacket Vespa virginiensis. Could be V. crabo or V. Germanica, but I doubt it. Way down the list is the honeybee A. melifera. If the halyards weren't given much oomph could be narrow-waisted wasps such as mud daubers, which isn't any challenge and won't do any damage to
wiring. But who knows? Every time some weird event happens I learn something.