They observed the details of anatomy, which they drew with great care. The 2 year old drew the great feathery antennae with more exactness than most adults could manage, because he really looked and wanted to draw them. Most of all, the children had TIME to do this, sitting on the patio in the golden Spring sunshine. Time is the key to Nature Study. He was not only giving us an example of industry, he was telling us to think.
True Science involves observing and considering, noting relationships and details.
The child who is watching ants in the backyard, or pigeons from the window, is doing the very best sort of science lesson available. When I was a child we had pigeons nesting in our gutters. We used an upstairs sunporch as a spare bedroom and playroom. I could, and did, lie on the bed and watch the activity in the nests. My brother and I also spent a lot of time in the nearby University Museum, where we discovered a large collection of stuffed pigeons.