This excerpt is from a space opera novel I'm working on:
Slowly, fighting every light second of the way, the defenders fell back towards the Vig home star. In the outer fringes of the system the fleet opened to pass around a particularly large planetesimal. The Purifiers did likewise.
"All right," said Peersh, seeing the Purifiers ignore the body and leave it unattended behind them. "Activate the Recursive Error."
Sensors on both sides showed flickers of activity at several locations distributed around the surface of the planetesimal, now at the rear of the Purifier fleet. This was initially ignored by the Purifiers. Then the activity began increasing, gradually at first but with an ever-escalating change of rate, heading for an asymptote. A group of the rearmost Purifiers moved to investigate. From stealthy, resistant probes the defenders had placed around and on the body, Admiral Peersh knew just what they were seeing.
The surface was in turmoil, and vast quantities of low-temperature neutrinos were being generated from all over the body to depths of multiple hundreds of meters. Even as the Purifiers investigated, the number of sources increased and spread, many burrowing deeper into the ice and rock. Remote sensors gave indefinite readings when they tried for detail. Therefore, the Purifiers sent probes down. Probes which ceased functioning seconds after reaching the surface, providing little additional information. More probes were dispatched, this time to cruise above the surface, through the thin atmosphere of cold hydrogen and fine dust being so vigorously stirred by the strange activity. For a while they were unmolested, sending back data on the disturbance which the defenders knew would prove frustratingly confusing. Then a long, segmented arm whipped up from the surface and grabbed one of the probes out of the cryogenic air. Shortly, all the probes were attacked by variations on that scheme. Most were destroyed, though a few managed to stagger back out of the atmosphere and return to their ships. During this period, the last of the probes placed in the body by the defenders was lost, much as expected.
"That's new!" said Cayle, his attention suddenly increasing at the appearance of the swatters.
"Well, it's helping us," said Peersh. "Look, more Purifier ships are moving towards our little diversion. The rest of their fleet is slowing, as well. Think I’ll have our ships stop here and mount a strong defense."
Probes equipped with tech jammers were sent down. They were immediately attacked by more grabbers, improved designs which used the best features of the previous generation, plus some new developments.
"Why are they going on the offensive like that?" demanded the Admiral. She spared the science/technology advisory team a hot look. "And how? You assured me the units would remain confined to the body, and that they had only limited AI functions."
"They look for resources and consume them," said Hudern, shrugging. "There are most likely materials on those probes which are scarce on the planetesimal. As for their unusual strategies, large numbers of modestly capable minds can form a gestalt, an effective neural net. They do share information."
"Look!" Cayle cried, pointing. "Those ships are falling apart!"
Two of the Purifier vessels were indeed crumbling away, the pieces evaporating in the familiar manner. Only this time they were leaving debris behind. Debris which was actually constructors.
"I bet those are the ones which took probes back in," said Peersh. "Those swatting arms must have had constructors on them!"
"I bet those swatting arms are _made_ of constructors," said Cayle. "Co-operating like ants to bridge a gap."
"Admiral," came a message from Tactical. "More of the Purifier fleet is diverting back to the planetesimal."
"That doesn't make any sense," said Cayle, puzzled. "They should know by now that if they just ignore the things they won't bother them."
"You can't expect them to reach that conclusion this quickly," said Peersh. "I'm certain I would want more data before leaving something like that behind me, even if I wasn't involved in a battle."
Over the next several minutes more and more of the attacking craft moved back towards the planetesimal and its odd inhabitants. Joining in formation, they began projecting destructive beams of various types down towards the icy protoworld. Huge gouts of material were lofted into space by some of these. While the activity was reduced by these endeavors, it was otherwise unchanged, and soon recovered its frantic pace. The simple machines took no apparent notice of the attacks against them, and did not alter their behaviors.
"Oh, God..." said Cayle, watching the constructor-carrying eruptions of material spray into space. "That... that is so stupid! That is just about the worst thing they could have done!"
His words proved prophetic. Over the next half hour hundreds of the Purifier ships were contaminated by the constructors, broken down by the diligent little machines to such an extent that their self-destruct characteristic was triggered. Yet more and more of the offensive fleet pulled back from engaging the forces protecting the Vig system to take position around the planetesimal, and continued to attack it in a variety of ways. Most of which served only to launch more of the worldlet's material into space, carrying constructors along for the ride.