Bugs, Stay Away From My Insects

Why do bees like Charlie's butt?
For a few days, Charlie left the bee girls alone. When it's warm, they're working. When it's windy and rainy, it's easy to get worried. They're up on top of a three-story building where, walking below, you can turn a corner and lose your hat, it's so gusty. They're nature, though. They don't need anyone poking around all the time bothering them.
You can check on them as long as you don't raise the bee roof and freeze them out. Charlie constructed his hives so there's a drawer-like pull-out he can open or shut to operate like cheap air conditioning (we call that a window): bottom boards. With the unusually cold weather, the bottom board has remained closed tight.
He's looked before and noticed what's fallen down in there. The bottom boards look like the ground under a construction project, which is what it is, with bits of pollen and shards of comb instead of wood and nails.
He started with the Golden Gate girls, the wild swarm he caught. They are the smallest, and their board was tidy and free of junk. Next he checked the Alameda girls, the bigger ex-wild swarm. Their bottom board looked like that of a big-city contractor, with lots of debris left from a hard day's work. The Oakland girls, two combined swarms, also looked pretty industrious if you were judging by the droppings.
The first of the store-bought bees, the Giants, had a normal-looking bottom board. The second, the Slackers', their bottom board was a mess and, worst of all, contained two dead varroa mites.
Varroa mites grab onto the back of bees' shoulders and eat their muscle tissue. They get everywhere and, like all parasites, eventually die when they kill the hive. Like all unwanted things, they breed like crazy. They’ll kill a hive within months. They’re said to be partially responsible for colony collapse disorder.
Finding two mites in a hive of 20,000 bees is okay, though. Varroa mites can come from anywhere, even flowers. They might have even found a free ride along with the bees' package.
Looking closer, Charlie saw more than mites. Crawling over the bottom board were little light tan, spider-like dots. Are these baby varroa mites? If so, he'd have to sugar-dust right away, or as soon as the cold air stops blasting the roof.
Sugar-dusting is the same as what you do to cake, and with the same type of sugar. The mites can't hold onto the backs of bees when they've been powder-coated with sugar, so they slip off. You have to do it a on a regular basis to get the baby mites and even then there's a good chance this hive is screwed.
Baby varroa mites don't look like this, though. They had fatter abdomens, were a different color and a different shape. Phew. They're something else.
He asked for help from the Organic Beekeeper's Chat Group. Even if you don't want advice, beekeepers on chat groups will give it to you. And none of it will agree.
"You're going to get spiders," people wrote in reply, "and all kinds of insects like that. It's a dark, warm place. They'll hang out inside the hive, mostly on the bottom board. If the bees don’t want them, don’t worry. The bees will get rid of them."
Spiders? He looked up photos of baby spiders. They looked like garden spiders; harmless and non-venomous.
He was planning to sugar dust, only inside on the computer while waiting for the wind to die down, until this. Opening a hive now would be bee-abuse anyway. Across the street, branches were breaking and crashing. Gusts of wind slammed and shook apartment windows all over the building. The fog was so thick that even if you were energetic enough to go outside, you'd have a hard time not being hit by flying something. Being in nature is like being unemployed: sometimes the best course of action is no action at all.