Strange mushrooms on lawn

I just found these all over my lawn. What are they? Will they harm my lawn? Any ideas much appreciated!

 

Look like puff balls which I get beneath one of my bamboos

 

I have always thought that mushrooms are generally a sign of a healthy lawn if anything, although we may often dislike their appearance.

Nick

 

I found a random couple of puff balls in my lawn last year. I removed them as I have a dog. They didn't seem to do any damage to the lawn. Its been fine.

 

thank you all for your replies I will leave these mushrooms in peace, at least for now