We have long thought of insects as mindless and robotic-like creatures.

The closer we look, the more complex the behaviors are, from bees communicating through dance to incredible feats of ant cooperation.

There are a variety of responses to unpleasant stimulation in animals. Pain perception can be one of these.

It is known that insects have avoidant responses.

The fruit fly showed symptoms of chronic pain after researchers removed its leg.

The fly's "pain brake" mechanism was lost, according to the authors. When the sensory nerves were overstimulated, the pain brake mechanism stopped working.

It's not as easy to detect pain in other life as it is to detect a negative reaction to a harmful contact. To register a feeling of pain we need a complex system that is connected to our brain and emotions.

In mammals, the nociceptors send an alarm for bad stimuli to our brains, which in turn causes us to feel pain.

Nociception and pain can be regulated by their own systems.

The systems haven't been fully identified in insects.

A hallmark of human pain perception is that it can be altered by the brain.

The body's own opiates suppress the nociceptive signal, making soldiers oblivious to serious injuries in the battlefield. We asked if the insect brain could make the experience of a pain-like perception plausible.

Several lines of evidence show that this mechanism is present in insects.

They don't have the genes for the opioids that regulate pain in us, but they do have other genes that can be used to regulate trauma.

Evidence shows insects have pathways that suppress their peripheral and central nervous system. bumblebees' normal avoidance of unpleasant stimuli is suppressed by the presence of a sugar solution

insect's defensive reaction against touch stems from the part of their nerve cord that is descending from the brain.

The tobacco hornworm uses grooming after being wounded.

Taken together, they seem to indicate that insects have a similar pain control system to us.

The team believes that insects have central nervous control over nociception. Control is consistent with the existence of pain.

It is possible that the complexity of their nociception regulation and potential feelings of pain are different between them.

The proposed mass farming of these animals in the future raises important ethical questions for further investigation.

The researchers say that we are at an important crossroads of how to feed a human population projected to reach 10 billion.

The United Nations recommends mass production of insects for food because conventional livestock farming is a major contributor to climate change. Since animal welfare protections don't cover insects, ethical implications have not been considered.

The research was published in a journal.