"Expendable", a short story by Philip K. Dick, first published in The Magazine of Fantasy and Science Fiction, July 1953, available at the Internet Archive. It was part of the (unaccepted) answer to this anthology-identification question.
The plot centers on an unnamed human being caught in the middle of the ongoing, million year conflict between the degenerate descendants of the insects (Earth's original inhabitants) and humans (the invading species).
"I see." The man nodded. He licked his lips, running his fingers shakily
through his hair. "Do you think — that is, what are the chances — "
"Chances?" The Stinger undulated thoughtfully. "Well, we've been in this work a long time. Almost a million years. I think that we have the edge over them, in spite of drawbacks. Our arrangements with the birds, and of course, with the toads — "
"I think we can save you," the Cruncher put in cheerfully. "As a matter of fact, we look forward to events like this."
From under the floor boards came a distant scratching sound, the noise of a multitude of tiny claws and wings, vibrating faintly, remotely. The man heard. His body sagged all over.
You're really certain? You think you can do it?" He wiped the perspiration from his lips and picked up the spray gun, still listening.
The sound was growing, swelling beneath them, under the floor, under their feet. Outside the house bushes rustled and a few moths flew up against the window. Louder and louder the sound grew, beyond and below, everywhere, a rising hum of anger and determination. The man looked from side to side.
"You're sure you can do it?" he murmured. "You really can save me?"
"Oh," the Stinger said, embarrassed. "I didn't mean that, I meant the species, the race . . . not you as an individual."
The man gaped at him and the three Eaters shifted uneasily. More moths
burst against the window. Under them the floor stirred and heaved.
"I see," the man said. "I'm sorry I misunderstood you."