Frère Rubik is sitting with his feet up on his desk at the F.R.I., half dozing as he gets mad gains in JP in Magikarp Jump. A small desk fan pivots back and forth slowly, ruffling the unkempt papers strewn around his office. This peaceful reprieve is rudely interrupted by the arrival of the Chief, who brusquely barges into the office and slams his hands down on the desk.
"FRÈRE!" he shouts, and Frère bolts backward in his chair, toppling over. On his way down, his foot kicks his computer mouse, waking his laptop up from hibernation and starting the Trololololo Song. Frère rights himself and hurriedly closes the tab, only to unmute another tab playing Smooth Jazz Nyan Cat. Vainly, he closes that tab, but in his haste he accidentally presses his secret keyboard shortcut which causes all of the computers in the surrounding area to play Epic Sax Gandalf. Frantically, he shuts his laptop, and the room is finally silent. Panting slightly, he looks up at the Chief.
"H-Hey there, Chief, what brings you 'round these parts?" he asks, trying to sound casual.
"We're shutting down the È-Files, Frère. Pack up your things!" shouts the Chief angrily.
Frère Rubik is aghast.
"But, Chief, you can't just shut me down! The È-Files are a valuable branch of this organization--"
"You've never even solved a case!" the Chief interrupts angrily.
"Well, that may be, but we've made some significant strides in explaining ghost spiders and random blood circles--"
"THOSE CASES HAVE BEEN STAGNANT FOR MONTHS!" the Chief cries.
Frère opens his mouth to protest, but as he does so a sticky note falls on top of his head, jarred loose from the wall by the commotion. He retrieves it and grimaces as he sees that it's the note relating to the Blood Circle case, dated 10/28/2015; it's been a year and a half. His shoulders sag glumly.
"That's what I thought," the Chief says, gruffly. "Gather all your stuff and head down the hall; you're being reassigned to the Folk Doctrine Division."
Frère winces as he hears the sound of wild banjos and Neal A. Maxwell quotations being shouted loudly from the neighboring offices.
"How does this even work, anyway?" he mutters to himself as he slides an empty box out from under his desk. "Is this entire organization just some weird manifestation of my subconscious or is it an independent entity unto itself--"
"Better if you don't think about it, kid," says the Chief, overhearing Frère and cutting him off, "this isn't the first time an introductory narrative has been more hole-y than a slice of Swiss cheese."
Suddenly, there is a loud "DING," indicating that a new question has come in. Frère pulls it up on his phone, not daring to open his computer again. As he reads it, his eyes light up in excitement.
"Chief! I've got a new case! The È-Files are here to stay!" he exclaims.
The Chief rolls his eyes.
"Whatever. Just forward it to general inquiries. I'm sure they can handle--"
"A TREE IS RAINING MAGGOTS FROM ABOVE!" exclaims Frère.
The Chief looks suddenly ill. He holds a fist up to his mouth, then makes for the door.
"Alright, fine, do what you have to do," he says, exiting hastily. "And Frère?"
"Don't send me the report on this one."
With that, the Chief is gone, and Frère returns to Magikarp Jump with increased vigor and vitality.
Please pardon my silly introduction. I just feel like I haven't been silly in a while.
Now, getting to the case at hand, I think I actually have a solution for you this time, Dee. For those reading that didn't follow the link in the question, it leads to a video download, from which I have taken the following screenshot identifying the critter in question:
As we can see, it is a very small (one might even say smol) worm-like thing, of a vaguely whitish/greyish/greenish/brownish coloration. When I saw the video for the first time, my gut reaction was that this was not actually a maggot. Due to an unfortunate mission experience involving dead raccoons and bleach, I've had the opportunity to see maggots up close, and this li'l guy seemed at least a wee bit different. See, maggots' bodies usually have bigger segments than this fella seems to have, and they also tend to be a more opaque white color (or even yellow), whereas the above crawly seems a tad translucent (in my experience, maggots also tend to be a bit bigger; I feel like they'd be longer than the diameter of that screw there). If you don't believe me, you may conduct a Google image search for "maggot" and compare the results, but I cannot recommend doing so because eeewwwwwwww.
So, if not a maggot, what is this little guy? I think the biggest clue lies in your question. You mentioned that these bug-o's are falling out of one of your trees, specifically an Elm tree. A bit of digging led me to this blog post, which seems to describe a similar phenomenon. The blog post reaches the conclusion that their creepy-crawlies are Elm Leaf Beetles in an early stage of development. Comparing their pictures to yours, the two look a bit similar, but not especially so. Another link I found suggested that they might be Spring and Fall Cankerworms.
Now, like the blog poster's friend said, I'm no Entomologist, and the closest thing we have to an Entomologist here on the Board is The Entomophagist, and he's more about eating bugs than identifying them, so I can't say for certain what your little friends might be. But, I feel reasonably certain that they are the early stage of some sort of beetle or insect and not maggots. If they're still dropping from the trees, you might consider catching one and trying to raise it to maturity to see what it might turn into.
Until next time,