Gray Catbird: A Very Smart Bird

A gray catbird but not the one I saw today

Today I was outside on my back patio doing a little bit of yard work. I swept a bunch of dead leaves and other yard debris and put them into a compost bag. In some places, these leaves had piled up, and I found earthworms underneath the leaves helpfully starting to decompose the leaves. Then I moved the compost bag, so I could work in another area, and I found more earthworms underneath the bag. [I honestly have no idea from where these earthworms come. Every time I sweep away leaves that have been there for a while, there is dirt and earthworms. Problem is, it is concrete patio surrounded by a brick retaining wall. How are these earthworms getting down the retaining wall and then getting across several feet of concrete patio?] I swept more leaves and put them in the compost bag. While I was doing this, I noticed a gray catbird (Dumetella carolinensis) land on the retaining wall then fly down to the patio near where the compost bag had originally been. This is slightly unusual because while I see a gray catbird almost everyday, I normally see it on the hanging suet feeder, not on the ground. Then I started pulling some invasive vines from my yard, and I noticed the catbird now land again on the patio, but now it landed in the second area that I had just swept right next to the compost bag. The second spot was about six feet or so from where I was standing pulling vines. I picked up the vines I had pulled and walk back to the compost bag to put them in it. By then the catbird had flown off, but while I was putting the vines in the compost bag, I looked back, and now the catbird was where I had just been pulling vines. I walked back to that same spot and swept the wooden steps that allow a path over the retaining wall. The catbird returned to the area near the compost bag. I then picked up the leaves and walked back to bag, and the catbird returned to the area where I had swept. This continued for a half hour or so. I would sweep or pull vines, and the catbird would watch me from the retaining wall. I would then take vines or leaves to the bag, and the catbird would return to where I had been working. The catbird was within about ten feet of me the entire time. I was actually quite honored that it would be that close to me. After quite a while, it finally dawned on me that the catbird was going to areas I disturbed to look for insects. I am not sure if it eats earthworms, but I was definitely unintentionally disturbing earthworms. I am fairly certain I was disturbing and revealing bugs. Thus, this very smart bird was letting me do the work of disturbing the ground to reveal insects, and the catbird would just come in my wake to look for the food. My new friend, the catbird, is a very smart bird.