I agree with those who say that Jake doesn't morph the Howler because they are "children playing in a battlefield." I think I, too, would avoid that morph except in the most desperate of circumstances.
As far as the "we won't morph a sentient being argument," I've never, ever liked that. It doesn't make any sense, at all. Sentience isn't about intelligence. It's the ability to feel or perceive. Sentience isn't caused by DNA but by the presence of a soul. The Animorphs can only morph the animal--they cannot morph a soul. An Animorph can look like a sentient being and have all the traits of being a sentient being, but they are still themselves. Their essence, their soul, whatever you want to call it, remains the same, and they do not gain a second one just by the act of morphing. Morphing has to do with the physical, not the spiritual.
And they HAVE morphed other people before. I remember the book where they crashed the summit with David and Marco had to morph a man. I don't remember them having an argument over souls and sentient lifeforms. They just did what they had to do.
Ethics are important and they keep us from becoming those we fight but I think that Applegate overdid it with the whole "we won't morph something sentient" argument. It always came off as contrived, to me.
