We poison our air and water to weed out the weak. We set off fission bombs in our only biosphere. We nailed our god to a stick. Don't fuck with the human race.
We drink poison too, and derive enjoyment from the temporary malfunctioning it causes in our higher brain functions. The higher the toxin level the greater the beverage; diluting the toxin with water is severely frowned upon.
Entire sectors of the Human leisure industry are dedicated to the production and sale of liquid inebriants which damage the body's internal organs and cause dehydration. Humans sometimes make a GAME out of consuming these inebriants.
We cover our food in neurotoxin. For the flavour.
Humans are so hardcore their first innovations were ways of making killing easier. Don't mess with homo sapiens sapiens.
Humans consider one of the greatest career paths available to be piloting conveyances that use explosions for thrust.
We routinely bombard ourselves with high amplitude sonic vibrations as a recreational activity. The more intense energy output used in this activity, the better the experience. Rock on Humanity!
The human taste in literature is highly disturbing, to say the least. While they have some civilised pieces, regarding philosophy and emotion, too much is simple obscenity. murders are glorified, and the more they kill, the more famous they become, while wars are remembered almost fondly, referred back to time and time again in tale after tale of slaughter and debauchery. What kind of race could revel in its own sociopathy?
Large and potentially dangerous doses of highly toxic chemicals and radiation are widely accepted as valid treatments for a variety of ailments. Even in medicine, the humans are exceedingly brutal.
The fact that Humans expose themselves to sunlight in order to damage their skin and make it assume a darker hue just adds weight to the theory that this species is in love with death.
Some humans even worship a insane sociopathic god that commits all kinds of atrocities like killing their own children and yet they consider this god to be loving and merciful.
You only have to look at the gloomy obsession with treatment of deceased humans in early cultures (see embalming, insistence on using 'special' ground to bury the deceased) to come to the conclusion that the entire race is close to being a violent death cult.
Their own physicians claim that, "it kills the same number of human and cancerous cells, but the human has more."
They do this with their own bodies! Imagine their willingness to expend people with whom they have no personal connection!
The various human cultures seem incapable of forming a single coherent whole as is the norm throughout the rest of the galaxy. Whereqas others formed a single coherent cultural whole for the species, the humans obstinately refuse to do the same and regularly indulge in brief but highly destructive bouts of intercultural culling.
The human capacity to change is fascinating.
I myself have witnessed a human military officer, who is tasked solely with the purpose of abusing his subordinates until they bond, take a group I suspected of severe genetic ailments - excess fat tissue, panic during crisis situations - and turn them into the perfect murder machines that have come to know and fear. We have long suspected that humans in their homelands are weaker than those we regularly encounter, but it is clear that even the weak ones can become dangerous with minimal effort.
I would not advise an invasion of any human-controlled system at this time.
Humans are an incredibly odd species. While most creatures couldn't dream of putting themselves in danger, they do it for the sake of health. They put all sorts of chemicals in their body to cure ailments. They don't even understand how any of it works. They simply know that it doesn't kill them, and they're happy with that. They even frequently experiment with new chemicals, trying to cure more ailments with potentially deadly ingredients!
Some humans even deliberately put themselves in incredible danger just for fun.
All human children, from the earliest stages of post-uterine development, are encouraged to partake in feats of violence and strife with one another, to establish which group is the victor. With no tangible benefit presenting itself, they compete purely for the sake of dominion and ego. Often these competitions will involve forceful physical contact and injuries, which is considered a part of the developmental process. It should come as no surprise that the species is so malajusted.
"Observation indicates that many of their tactical simulations- used to desensitize their offspring to violent actions- are not given freely, but instead must be purchased of the offspring's own time and money. In this way, training for what is often bloody combat, simulated homicide, and sometimes even wanton acts of destruction is seen as a sort of commerce and reward."
It has been suggested that the harsh environment the human species originated in is responsible for much of their aggression. The environment of Sol-3 (or Earth, colloquially) is volatile in the extreme. Massive salt water oceans are pulled about the surface of the planet by lunar tides. This combines with a constant colossal movement of air about the planet to make storms of mind boggling size and ferocity. “Hurricane” is a water/air hybrid storm that flings masses of water and air about, sometimes leveling or flooding whole cities. “Tornado” is an electrically charged vortex of winds that can demolish even the strongest human structure, yet they commonly build vast both vast cites and, even more astounding, clusters of flimsy dwellings called ‘mobile homes’, in areas renowned for the violence of these storms. The planetary temperatures create both vast areas of frozen water and dehydrated desert, and humanity has filled even these inhospitable climes with everything from crude structures hand made of local materials to large ‘resorts’ where humans PAY to subject themselves to prolonged exposure to solar radiation or swim in large tubs of water filled with chlorine!