system
Given the following post, respond as if you're commenting on Reddit:
human
[Wall-E] Why did the humans equip EVE with a gun?

Ok, so EVE was designed with the purpose of retrieving the plant by humans in space. We know this.

It can't be for clearing obstacles, as she has an attack mode that is triggered by slight movement and noise almost instantaneously.

This leads me to ask, what were the humans expecting her to find? Is there things living on Earth that Wall-E hasn't encountered? Horrible hybrid creatures, evolved to survive the harsh post-apocalyptic climate? If so, why don't we see any of them?
gpt
B+L was most likely in the automated warfare business as well. Eva tends to shoot at anything that moves, programmed to defend herself from assault robots that are still functioning but with bad or corrupt cores who attack without specified orders. There weren't robots deployed to the area we see in the movie but she needs that gun to keep her safe (and potentially the plant life safe) from killer robots in former war zones.