Animorphs: The Attack, sample.
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This last was directed at the press of a dozen Iskoort, all yammering incessantly.
<I will buy your memories!>
<Come visit my execution parlor!>
<Give me your clothing and I will give you credit!>
<Here! Eat this larva! Let it gestate and we'll split the proceeds between your heirs!>
<You stink horribly! I will cleanse you!>
And to Ax: <Become my partner and we will sell your fur as a gachak poison!>
"What is this, Planet of the Salesmen?" Marco demanded. "Back off! All of you, back off!"
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So yes, they use thought-speak.
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