How do you open a mussel?

It was quite windy this morning so I decided to walk instead of cycle to the supermarket to do my shopping. I was hoping to find something to blip on the way there or back and was glad when I spotted this Gull, which was trying to figure out how to open the mussel it had found. Unfortunately it lost the mussel again just after I'd taken this photo as it fell into the water in the process.

I had to do the shopping in the morning because I had to work in the afternoon and evening.

Thank you so much for the kind comments and stars on yesterday's sky blip.