Every study performed on insect counts has concluded that overall insect populations are declining, though there is not complete global coverage of data. One study in Germany found that the flying insect population had decreased by 75% from 1990 to 2015.

A 2019 survey of 24 entomologists working on six continents found that on a scale of 0 to 10, with 10 being the worst, all the scientists rated the severity of the insect decline crisis as being between 8–10.

Nothing scares me quite as much as the thought that I might live to see global ecological collapse.

There is a possibility that the Higgs field isn't at it's lowest energy state, and that a random quantum tunneling event could drag the Higgs field to that lower state. In this unsettling scenario, a bubble pops into existence somewhere in the universe. Inside the bubble, the laws of physics are wildly different than they are outside the bubble. The bubble expands at the speed of light, eventually taking over the entire universe. Galaxies drift apart, atoms can’t hold themselves together, and the ways that particles interact are fundamentally changed. Whatever form the universe takes after this event certainly wouldn’t be hospitable for humans.

If you separate the halves of your brain, they can operate relatively fine independently of each other, each controlling roughly half of the body. When one half does something, and the other half is asked why they did it, the other half will make up a plausible reason why they just did that action. There's a theory that this is basically how your brain works all the time, just guessing why it did things, and potentially with multiple processes happening in relative isolation that aren't consciously aware of each other.

Microbiology can be so much fun!

Streptococcus pyogenes causes a flesh-eating disease (necrotizing fasciitis). This species of bacteria releases toxins that kill living tissue, so you better make sure that paper cut doesn’t get infected.

Mycobacterium tuberculosis is famous for a bunch of different pandemics over the centuries. If you thought covid was fun, imagine coughing up blood.

Clostridium botulinum is special, because it produces a very spicy toxin, so you don’t even have to ingest any living cells or spores of C. botulinum to get killed by it. If you do, you can even have your very own toxin factory inside you.

Vibrio cholerae is another classic responsible for numerous pandemics. This one is a bit different, because it involves lethal amounts of diarrhea.

Oh, and the scary bit? There are people who don’t believe bacteria or viruses exist. They actively oppose taking measures against these things. Humans can be truly horrifying at times.

Gamma ray bursts from celestial events such as a supernova. One of these - GRB 221009 released 1,000 times more energy in 5 minutes than our Sun has emitted throughout its 4.5 billion year life. GRBs from different galaxies have set off detectors on earth designed to detect nuclear explosions. One of these in our galaxy, pointed directly at earth could end all life on it. https://en.wikipedia.org/wiki/Gamma-ray_burst

Each year, is about a 1/2 of 1 percent the sun will give out a flare so big, it will not only destroy all power distribution to the half of the earth exposed, and destroy the internet there, but cut off food distribution, starving most of the population in any county . Last time it happened was in the 1800s but no stuff to destroy then. And food was local.

It would be years before things were normal . Our current setup is literally doomed to failure for a random half of the earth

Combinatorics scares me, the immense size of seemingly trivial things.

For example: If you take a simple 52 card poker deck, shuffle it well, some combination of 4-5 riffles and 4-5 cuts, it is basically 100% certain that the order of all the cards has never been seen before and will never been seen again unless you intentionally order them like that.

52 factorial is an unimaginable number, the amount of unique combinations is so immense it really freaks me out. And all from a simple deck of playing cards.

Chess is another example. Assuming you aren't deliberately trying to copy a specific game, and assuming the game goes longer than around a dozen moves, you will never play the same game ever again, and nobody else for the rest of our civilization ever will either. The amount of possible unique chess games with 40 moves is far far larger than the number of stars in the entire observable universe.

You could play 100 complete chess games with around 40 moves every single second for the rest of your life and you would never replay a game and no other people on earth would ever replay any of your games, they all would be unique.

One last freaky one: There are different sizes of infinity, like literally, there are entire categories of infinities that are larger than other ones.

I won't get into the math here, you can find lots of great vids online explaining it. But here is the freaky fact: There are infinitely more numbers between 1 and 2 than the entire infinite set of natural numbers 1, 2, 3...

In fact, there are infinitely more numbers between any fraction of natural numbers, than the entire infinite natural numbers, no matter how small you make the fraction...

Some species of snails are infected with a parasitic flatworm called Leucochloridium paradoxum, which has a life cycle that involves manipulating the snail's behavior and appearance to increase its own chances of survival. The parasite causes the snail's eyes to turn into worm-like protrusions, which are actually just the parasite's own larvae.

To birds, these worm-like eyes look like tasty little morsels, and they'll often peck at them to eat them. But in doing so, they're actually ingesting the parasite's larvae, which then complete their life cycle inside the bird's digestive system.

There are about the same number of bacteria cells in your body as human cells, and some of the bacteria in your intestines, 'gut biome', can affect your preferences for certain foods effectively controlling your mind.

A 'reference man' (one who is 70 kilograms, 20–30 years old and 1.7 metres tall) contains on average about 30 trillion human cells and 39 trillion bacteria,

https://www.nature.com/articles/nature.2016.19136

Is eating behavior manipulated by the gastrointestinal microbiota? Evolutionary pressures and potential mechanisms:

https://onlinelibrary.wiley.com/doi/full/10.1002/bies.201400071

That probably freaks me out just as much as time passing not being fundamental under B time indicated by general relativity or free will being illusory and the universe is more likely deterministic.

Read the Wikipedia article on Radon. That should do the trick.

There is a legally permissable organic contamination amount in any food, especially if it's processed. Bugs, hair, nail clippings, dirt, mouse shit, whatever - all ground up and processed asking with the product. And it can be in almost anything, including that one you really like.

When you die, ants go straight for the eyes.

You can try taking a look through the different forms of torture or execution humans have used...