crabs off Inniscrone pier

Hi ,
Not sure if this is really an angling Q but was talking to a bloke I couldn't fully understand - think he was telling me that a couple of wks ago they were hand-lining large ( dinner plate size ) crabs off the end of the pier . Apparently one claw much bigger than the other .
Spiders ????
Annual event ???

cheers
nick

Spiders I would say as there is a big influx of them down my way at the moment.