Caterpillars have destroyed lawn!

Over the past 2-3 weeks our lawn has tournée bare and brown. We discovered the problem this morning … a massive invasion of caterpillars (armyworms??). There are thousands of them in the ground, it’s horrific.

Has anyone had a similar experience / can give advice on what to do? Ideally we deal with this problem ourselves.

We are in 06, Alpes Maritimes.

We go to our garden centre tomorrow for help and advice.

Thank you!

Chickens - free ranging