What is this?

Recently, we’ve found lots of these small grub/maggot things on our patio. We first noticed them one morning. My wife lifted up a patio mat and there were dozens.

I got rid and have seen the odd one but this morning we found 4-5 all at different spots.

My first thought is leather jackets but wanted to check. Should we be concerned? Anything we should do?

Many thanks.