Why I Can't Mow Inside My Chicken's Pen

I've been wanting to get out and mow the tall grass inside my chicken's pen.  I feel like they're not utilizing all the area they have because they can't get through the grass to catch bugs. 

But then yesterday morning, while I was feeding the chickens, a hen came out of the tall grass and I heard peeping.  

After looking around through the weeds I found three little chicks!  I was able to catch one and take a picture.  

Then with some poking around, I found the nest buried deeply into the bottom of some weeds.  

I don't know if the hen is still sitting on the remaining eggs.  I guess I'll find out in the next few days!

While I was looking for the hen's nest, I found another nest.  I don't know what bird's eggs they are, but they're pretty small - about the size of a robin's egg.  

And this is why I can't mow the grass in my chicken pen!  I don't know how many other nests might be hiding in that tall grass and I sure would hate to destroy them!

Now I'm trying to decide if I want to take the new little chicks inside under the heat lamps or leave them with the hen.  The mortality rate is much, much higher if I leave them with the hen so I think I may try to catch them.  

Three very wet chicks came out of the weeds this morning.  The other hens were not kind to them and I decided they had a much better chance of survival if I brought them in and put them under lights.  So far they are thriving.  

Research tells me the eggs in the bottom nest are bobolink eggs.  We've had a huge uptick in their numbers this year!