"An oak-tree seems to be a regular city," said Frank.
"Look at this marvellously beautiful fly, with lace-like wings," said Jimmy. "What is that?"
"That is a lace-wing fly," answered Dick. "Just put your nose as close as you can to it and smell it."
Jimmy did so, and said,—
"Why it is nearly as bad as a stink-horn fungus."
No more ducks came back that day, but three more wood-pigeons fell victims to their love of corn, and the boys descended, by and by, and walked home.
As they were sitting on a stile, Dick pointed to the carcase of a mole which lay on the path, and to two little black beetles with yellow bands on their wing-cases, which were crawling over it.
"I think those are burying beetles. Let us watch them. They lay their eggs in dead bodies of beasts or birds and then bury them, and the grub of the beetle lives on the carcase in its babyhood."
They lay down on the ground by the beetles, watching them. The process of egg-laying by the female was just about being completed, and the two soon buried themselves in the earth beneath the carcase, and presently appeared at one side with a little mound of earth which they had excavated from under it. This process was repeated again and again, and very slowly the mole began to sink into the ground. The boys watched it for nearly an hour, and in that time the mole was about half-buried. One observer once kept four of these beetles in a place where he could observe them, and supplied them with carcases of small animals and birds, and in twelve days they had buried no less than fifty!