Are you sure it isn't the birds pecking at the buds to get the bugs and damaging the flowers as a result.

I have seen birds, squirrels slugs and snails all at mine. a slug was 'asleep' inside one of my doubles. it is never going to wake up now.

Thanks ladies - I'd never thought of that - seems to explain it unless someone has a different idea.

So many of my daffs have been munched this year that I have deadheaded almost as many as bloomed. I always put it down to slugs but as MG and SBG say, it could be any number of critters.