Yes. Morphing mages is inferior to being one in a bunch of ways, especially the time limit, so if they're working with mages, morphing them is not a high priority. At least until someone works out a composite morph that's an Andalite with Gifts, and no one here has the talent for morphing to manage that.

...Wow, fascinating, the fact that anyone can do that has implications that Leareth doesn't have the spare attention to chase down right now but finds so intriguing. 

He goes to bed early and sleeps a candlemark longer than usual and has the weirdest math-dream-logic dreams, all of which are familiar outcomes from spending two consecutive days using his brain very hard. In the morning he gets on his communications-artifact again, unsurprisingly finds that everything is running smoothly, and then asks his Healers and the Andalites they're working with on Yeerk precautions how their work is going and if they need anything before he disappears for the rest of the day. 

It's going gruesomely. Working off animal models, Yeerks denied an ear canal can try an eyeball, which is really hard to prevent them from being able to do. (Noses are possible to pinch small enough to not let them in.) They aren't sure whether it's worth doing at all, if you can't make it categorically impossible to infest someone, but it'd certainly prevent fast casual infestation which might be worth it for some operations.

The Andalite who can morph Yeerks hates his life but is available for experiments with what Yeerks in people look like to magic, and whether they can be separately compulsioned, if Leareth wants to do those now. 

Sure, now seems like a good time to do some Yeerk-looking, he may not be good for much by the time he finishes his Void-exploring plans today. 

His Healers confirm that they can see Yeerks, though they need to be actively looking with Healing-Sight, it's not glaringly obviously at a glance. 

The one Andalite will turn into a Yeerk. Does anyone want to volunteer to have him in their head or can they just do animals (he'd prefer that.)

One of Leareth's mage-gifted volunteers is curious enough that she'd opt in for it, especially since there's a slim possibility it'll give the Andalites another angle on the Gift-morphing. Does Leareth think this is all right? 

Leareth personally sees no problem, he trusts this people not to run off with his mage (mostly because he's mindreading them) and the Andalite can't stay in there more than a couple of candlemarks anyway due to morph time limits. He glances at Matirin, though. 

It's permitted with consent and a mindreader on hand to notice immediately if consent stops; they have that, so they're allowed to proceed.

The Andalite morphs into a horrible little slug thing, thin and greyish and possessing no real defined shape; someone has to hold it up to the volunteer's ear. If she still wants to do this.

She looks mildly grossed out but also still very curious. She's up for it but does want a warning if it's going to hurt? 

Reportedly it does not hurt, because they have a natural anaesthetic, one of the other Andalites tells her. The Andalites are having a very hard time being professional about the Yeerk even though the Yeerk is literally their colleague.

The Yeerk goes in. 

It takes about thirty seconds. it doesn't feel like much of anything, unless you try to move, in which case it feels like that's much much harder to do than it's supposed to be, and eventually impossible.

<Sorry. Not trying to - hold onto everything - it's kind of instinctive - I'm going to try to let go of your arm now ->

This is the most fascinating experience she's ever had! It's not entirely dissimilar to a compulsion, which she and her fellow mages practiced on each other in training so she's familiar with the test concept and not very bothered. She tries to move her arm. 

Can the Andalite-Yeerk find her Gifts? She tries to figure out if she can find them herself. 

Leareth confirms quietly that she seems fine so far and hasn't given any sign of revoking consent. 

He can figure out her Gifts (and stop her from accessing them). He takes a little while, then does a shaky mage-light. <I think an actual Yeerk would learn faster because they'd be trying to - grab all the host's memories and experiences ->

Good to know. 

Would it feel like anything to have a Yeerk grabbing all her memories and experiences? 

- he's not sure. He can do it if she wants? Then she's know how it feels but also he'd have grabbed all her memories and experiences. He's already getting a lot, just from incidental stuff that comes up as he tries to figure out how to use the body. He's going to be better at morphing human after this.

(They can communicate in this fashion, easier than Mindspeech, just shoving thoughts at each other).

She thinks this is probably fine because she doesn't know a lot of important strategic secrets and they're all ones the Andalites already know anyway, and it's not like she cares if an alien finds out about her childhood memories. She thinks loudly for Leareth, though, to ask if this is okay. It seems pretty valuable, honestly, if it helps Andalites learn to convincingly pass as human. 

Leareth agrees that there are no non-obsolete sensitive secrets this mage knows, and it does seem really valuable to give the Andalites some high-bandwidth lessons on human-ing. 

So the Andalite - reaches, with all of a Yeerk's senses built for this, for everything she knows and has done and can do, and it's fun, is the horrible thing about it, the Yeerk senses are delighted and satisfied and impressed and awed and vaguely affectionate - that part is presumably not Yeerk instinct - 

- and now the Andalite can do Gates, hah, watch.

The Yeerk species would be SO COOL if they weren't evil, damn, is what Leareth's mage is thinking. 

"I want to try my part now," Leareth prompts. He's already been watching both minds; to Healing-Sight they're blurred together and indistinct, according to his personnel, but to Thoughtsensing they're very distinguishable, albeit weirdly overlapping.

:I am going to try to place a compulsion on you and only you: he tells the Andalite-Yeerk. :It will be a very simple one, if it works you will find it quite obvious, and I will take it off after thirty seconds, but I want you to try on your own to figure out what the limits of it are, to give me information on how detailed I can make it for a Yeerk. Is that all right?: 

<Yes.>

So he does his best to zero in on the Yeerk-Andalite mind and not the human host, and places a careful compulsion - do not Gate, do not walk or move your feet at all. Everything else is fine.

:What do you notice?: