So in addition to fruitbats, there's vampire fruitbats in Equestria; they can benefit you if you set aside some apples for them to eat, but if you don't, they can ruin your entire crop in a day. (Apparently it'll all grow back completely the next day, though.) True to the old trope that "beautiful/pretty = good" and "ugly = evil", they look fairly ravenous, rather like gremlins. Well, unless Fluttershy's singing about them: then they look more like regular (cute) Equestrian fruitbats.
Speaking of singing, it was very nice to hear another song — and an Applejack/Fluttershy duet at that (that's a first, right?). I like these back-and-forth songs that essentially take a conversation and put it to music, too. Kudos to Daniel Ingram for a job well done!
Applejack cares deeply about her farm, but in the end she cares even more deeply about her friend, and when she needs to give up the prize apple she's been growing especially for the Appleloosa state fair, she does not hesitate one moment to do so. I thought that was very nice, especially after she previously played hardball with the bats. Fluttershy, meanwhile, gets props for standing up to Applejack (that is, if you don't mind) and pointing out that the vampire fruitbats are just critters that need to feed themselves and their young (um, if it's okay with you). She really loves animals, doesn't she. (Thank you, Captain Obvious!)
Rarity was a bit shallow in this episode, or so I felt; she fell into the "ugly = bad" trap head over feet (hooves?) and seemed very eager to declare the vampire fruitbats evil. The others did the same, of course, but at least they only did so because of Applejack's argument that they're pests (the bats, not the Mane Six).
Pinkie was being cute and silly without being ridiculously zany. Apparently she's able to hold things with her mane (don't ask me how; she's just being Pinkie Pie), and she can also dig holes and tunnels at ridiculous speeds; but she's also bouncing along happily and maintaining a cheerful attitude no matter the situation, as befits the Element of Laughter. I particularly loved the ♪ Fruitbat Roundup, Fruitbat Roundup ♫ bit — that was spot-on for Pinkie, and it was a cute reference to a wonderful song from way back when, too. (The second one in this season, in fact. Discord, I'm looking at you!)
Twilight appears to not yet have taken the lesson from Magical Mystery Cure to heart: be careful with your spells, they might have unintended effects on your friends. Fortunately, deprogramming Fluttershy worked without a hitch after they managed to round her up. It also turns out that THE STARE will work even when Fluttershy isn't intentionally using it.
It was nice to see the ponies use their friendship journal (although I note with amusement they enlisted Spike to do the actual writing), and it was even nicer to see that many of them likely learned something this episode. Applejack learned that not every animal that needs to feed is a pest; Fluttershy learned that when you feel that something is a genuine bad idea, you may have to say "no", even to your best friends; and Twilight (hopefully!) learned that removing the very essence of its being from a creature is not a good idea, even if your intentions are noble.
There were several references to the show's ongoing continuity; the fruitbats themselves are the most obvious example, but Fluttershy's stare and Dashie's insatiable thirst for cider (cider! cider! cider! cider!) also come to mind. I always like that: it shows that the ponies are living in a realistic world and leading actual lives. In too many shows, the characters basically do a factory reset for each episode; MLP:FiM is different, and that's one thing that makes it stand out so much.
Two things I didn't like so much: Twilight using what was essentially a magical computer screen to explain how her initial spell went wrong (really, Equestria doesn't HAVE that sort of technology: shouldn't she have conjured a blackboard or so instead?), and the "everybody laughs" ending. Well, I dislike those in general, but I do have to give the show credit for at least providing a good reason why they all laughed: Pinkie's "I vant to suck your juices!" vampire bat impression was pretty funny.
Finally, there were Fluttershy's canines, becoming pointy again right at the very end. Between this, the mysterious cloaked
All in all? A+ fun episode would watch again.
Elsewhere: discussion in broniesaremagic. Episode follow-up on EqD.