Chickens digging huge holes

They dig!  It's their natural behaviour. They scrat about looking for grubs, insects, worms etc. They also like to have roll about in soil as it helps keep them cool. They will flick soil all over themselves til they're practically buried in it.  It's what chooks do so you just have to go with the flow.  They will still need their layers rations and plenty of water, grit and regular supply of greens 

My run looks like the Somme as my girls have excavated so much! I tend to leave it alone (apart from poop picking and a bit of freshening up with Stalosan/Biodri and wood shavings from time to time) as ANHBUC is right - they are very quick to dig the holes again. I do have to check that they are not trying to tunnel out 

I am thinking of putting them in a moveable run during the day on my soon-to-be veg patch as they are so good at turning over the soil into a fine tilth and getting rid of weeds (adding manure as they go!). It will save me a bit of digging! 

Our 9 are free range (hectares available) and have pellets, corn and grits. They still dig huge holes in the most inconvenient places - like just in front of the garage! But.. you try digging a hole. Turn your back for 5 minutes and they've filled it in again. It seems to be something they enjoy.

Thank you all for your comments.  Looks like life is just going to be, well ... holey!!  But I am concerned about their eating - or apparent lack of.
Just to respond to a few points.
Grinling - Yes - they do have a pot of grit (sorry forgot to mention that).
ANHBUC - They are pure breeds - not hybrids and are only one year old.  One (Buff Sussex) has gone broody at the moment, so I can understand the lack of eggs from her.  But that still leaves 2 (a Light Sussex and an Appenzeller) not laying.  Only the RIR is laying.
ANHBUC - Yes - they do eat some of the NedzBed - especially when it's fresh - but I think that's because it probably still has some seeds in it.  Might try miscanthus or something like that.
Elvira - Yes - I use Stalosan too to keep the run disinfected.  It's good stuff.

So - the holes we are going to have to get used to.  But I can't get used to them not eating their pellets.  They used to clear out their food bowls every day (as well as treats of greens and kibbled corn), but now hardly touch them.  They used to be very good layers too!!  I know pure breeds can have times of not laying, but .. times of not eating??

Well I guess they must be finding something to eat down in the ground, because they certainly aren't short of energy!!

Thanks everyone .....

Their layers intake may well reduce at this time of the year. There will be more natural things to eat and they do not need food to keep warm, however, this is usually off-set by the need for food in order to lay. I'm sure they will settle down and re-start. Definitely agree to stop feeding them anything except layers for now