What can be nibbling along outside flower stems?

[EmNetta]

It's always the pinks which get stripped first, but I've yet to see anything that shouldn't be there. Garden after garden, year after year - can anyone suggest what this particular muncher might be? Or how to stop it please?

Slugs

Apparently broken eggshells and coffee grinds help?

Well, thanks for the info, and will certainly have another go with the eggshells. I've been using old coffee-grounds to boost various flowering plants, ever since I emptied them onto an old rose last winter, and saw the most amazing new growth and buds. I know there are slugs here,(and big snails), but this would explain why I've not seen anything munching or hiding on these plants. Thank you again for solving this old mystery.