why my dog scratches

[memaham]

why does my dog always have to scratch the survace before she lays down

[Shellywba]

Don't dogs do that because they want to make sure their surface is clean?

[medico]

She's making a nest for herself. Instinct overrides a dog's (small amount of)common sense.

[Eno-Missy]

I believe Medico is right.. you will also notice that most dogs will circle once before lying down. This is their instinctive reaction to flatten the long grasses from years ago in order to nest!!