Fish, reptiles, birds and mammals all have the limbic system in their brains which causes emotions. But what about bugs? Like insects, arachnids and crustaceans. They have much simpler brains. But yet, when you lift up a rock in your garden some bug will run away and seek new shelter. I doubt this bug is making the rational decision to find a new shelter, its reaction resembles fear. So, do bugs feel emotions?
There’s no evidence of such. Scurrying to hide when exposed to light is just a programmed reaction to a stimulus. Of course the reaction resembles fear, but I doubt the insect actually understands that a predator might eat it.
Agreed, insects react instinctively based on various stimuli that trigger fight, flight, reproduction, etc.
If it starts raining I will run to find shelter, this resembles fear, but I’m pretty sure it isn’t. I’m not saying this means bugs have a non-fear emotional response to being uncovered, I’m saying your rudimentary evaluation of bug motivation would fail even for evaluating human activity.
Normally, yes, but right after I’ve had my hair done for an evening outing? Oh, yeah! 
A lot of people used to say that what looks like emotional reactions is only a programmed response in everything other than humans, though. I think that’s pretty clearly wrong.
I don’t know whether we know enough about how insect brains work to know whether there’s some other pathway that would produce something that might reasonably be called “fear”. I doubt it would be exactly the same as fear in mammals; but I don’t know whether there’s some sort of equivalent.
You mean like René Descartes?
(Warning: do not read if you love dogs. Or loved Descartes.)
https://knowledgenuts.com/2013/09/29/descartes-dissected-his-wifes-dog-to-prove-a-point/
The presence of a structure like the limbic system is not evidence of phenomenon analogous to our experience. Humans have a terminal nerve, but it doesn’t seem to do much in our species.
Some insects demonstrate a hive mentality, which also at times can seem like emotions.
Wasps seem to get angry and chase you down when you just miss smashing them with a flyswatter.
This was demonstrated by wasp experiments. There’s a species of wasp, the Great Golden Digger Wasp (aka Sphex ichneumoneous) that paralyzes other insects and brings them back to its nest to eat them. And before it enters its nest, it will put down the paralyzed insect it’s carrying and look inside its nest to make sure no other predator has hidden inside while it was out hunting.
This looks like rational planned out behavior. But scientists have done experiments. When the wasp is inside checking its nest, they’ll move the paralyzed insect a couple of inches. The wasp emerges from its nest, sees its meal isn’t there, sees the meal a couple of inches away, goes over and carries the paralyzed insect back to its nest…
…and then it checks inside its nest again to look for hidden predators.
Scientists have found that they can do this dozens of times in a row and the wasp will never figure out the pattern. It’ll never be able to remember that it just checked its nest and it “knows” it’s safe to enter without checking again. Nor will the wasp ever remember that it keeps putting down its meal in one place and finding it moved when it emerges from its nest.
What appeared to be rational behavior turns out to just be a developed instinct. The wasp isn’t thinking; it’s just following a process that’s been imprinted on its genes.
And it’s safe to assume the same is true about emotions. Insects don’t feel emotions just like they don’t think. They might take actions that resemble the products of thoughts or emotions but those actions are just programmed behavior.
Sick bastard!
What a drunken fart!
“Have you ever heard of insect politics?” A line that has creepily stuck with me since watching The Fly.
I’m not sure I understand your argument. Animals without the neurology for certain experiences will not have those experiences. A limbic system or something akin to it seems to be necessary for an emotional life.
Perhaps necessary (although even that’s uncertain), but certainly not sufficient.
Correct
When I was a kid I raised insects, especially praying mantises. When I watched them having sex (voyeur!), I was always amazed that the male just kept going, seemingly unconcerned that his mate had just bitten off his head.
Then again, there are also some who would say that human emotions are just programmed instinctive responses, too. Our programmed instinctive responses can be much more complicated than most other animals’, but they’re still programmed responses.
To that end, I would say that insects do have emotions; they’re just extremely simple emotions. Fear is already one of the simpler human emotions, and the insect version of fear is even simpler yet.
For fuck’s SAKE, people, this is General Questions at the Straight Dope. Silly clickbait links about how René Descartes, who never married, allegedly “dissected his wife’s dog” do not belong here.
If you want to read a more GQ-worthy account of Descartes’ views and practices with regard to vivisection, try this one.