We will have to work hard at getting them to drop in.

We can hear them, but not see them.  

I always had walnuts in a container in my bag.  I had to go through the carpark to get to daughter's, and there were lots of gum trees there for them to hang out in.

Once they spotted me, they would want their walnuts and then follow me back to daughter's for more.  It was only a small container.

They nested in a gum tree 2 doors down from daughter's.

When the place sells, they'll drive the new owners batty, calling for their walnuts.

Sometimes all 3 had a loud chorus going.