Does this indicate alien activity?

Over the last week we noticed that something was happening to our front lawn. Part of it appeared to be covered in bits of grass or moss.

Like this.

We came up with various reasons for this peculiarity and didn't worry too much about it.

Sunday morning, husband got out the mower and by munchtime the lawn was bit free (that should read lunchtime but is quite an appropriate typing error).

By tea-time this is what the lawn looked like.

Husband thinks it is a squirrel burying his nuts. But that is an awful lot of nuts. And, surely, in the course of an afternoon, we would have spotted a squirrel at some point? Unless it is an invisible squirrel.

Harvey was named after an invisible white rabbit. At least I assume it was a white one but I have no reason for that. But I digress.

I am more inclined to the alien activity theory.

This says that miniature aliens have inhabited that area of our lawn. There is nothing - apart from Doctor Who - that says that aliens have to be huge terrifying monsters, so ours landed some time ago and have been busy creating a new biosphere for themselves. I don't mind in principle: I am just as prepared to share my home with aliens as I am to share it with spiders whose webs I do not have the heart to destroy. However it does make the lawn look awfully messy. It wouldn't be so bad if it were the back garden but this is right next to our front door.

Oh! There's a magpie on the lawn! He is searching for aliens. Either that ... or he is the one responsible for the mess.