In the Animorphs series book series, you see them change into mosquitoes, fleas and all sorts of small creatures. Could they go into single celled organisms?

Also, when they changed into mosquitoes, they were flung back into space because they were so small, yet that didn't happen with fleas. Would they have the same issues when changing into smaller creatures?

  • 14
    Awesome, an Animorphs question! Suddenly I'm in 6th grade again. Excuse me while I go spend 8 hours on Wikipedia, wandering down Memory Lane.
    – Nerrolken
    Commented Jan 26, 2015 at 23:18
  • 3
    @Nerrolken Even better - animorphs.wikia.com/wiki/Main_Page! Brings me back, too.
    – HDE 226868
    Commented Jan 26, 2015 at 23:19
  • 2
    @Nerrolken It was just a random question that popped into my head, figured this was the best place to ask it.
    – CBredlow
    Commented Jan 26, 2015 at 23:34
  • 5
    They were flung into Z-space as mosquitoes because of the Andalite ship's gravity field (or engine, I forget) affecting their extruded mass
    – Izkata
    Commented Jan 27, 2015 at 0:27
  • 1
    @Izkata: This, of course, occurred because Ax had just pointed out a few pages before that it was 'technically possible but extremely unlikely'. In other words, it was a million-to-one chance, which we all know works 9 times out of 10.
    – Jeff
    Commented Jan 28, 2015 at 15:13

2 Answers 2


I have read every single book in the Animorph series, and can confirm there is no canon explanation of a size limit to a morph. The mosquito incident, as @izkata said, was a special phenomena due to a circumstancial sequence of events.

  • 3
    I agree; but another point to consider is that their thoughts are affected by the creature they turn into (ie, they lose themselves in the hive-mind when turning into ants for the first time), so it's possible that they could physically change into a single-celled organism, yet lack the mental capabilities to change back. I remember one of them (Marco, I think) expressing similar concerns about the possibility of turning into a tree. None of them tested it.
    – Liesmith
    Commented Jan 27, 2015 at 18:02
  • 4
    Given that the process of acquiring is not automatic, but demands that you focus/intend to do so, it's entirely possible that the size limit is one of perception, not strictly mass. If you perceive something as a creature, you can acquire it (given that it has DNA, at least). This could explain why they never acquire the single-celled bacteria upon any creature they touch, but instead acquire that creature.
    – Jeff
    Commented Jan 27, 2015 at 18:21
  • 1
    All good points, but unless I misunderstood the asker, this question referred to a limit due to the technology, not the psychological issues involved.
    – Ender
    Commented Jan 27, 2015 at 21:45
  • 1
    @jeff your comment in particular is an amazingly good point, as perception is necessary for the dna absorption process to work
    – Ender
    Commented Jan 27, 2015 at 21:47

Single cell organisms

According to KA Applegate, animorphs can morph single cell organisms. As others have pointed out the incident in book #18 was due to a specific sequence of events, and not just because of the size of the morph.

The only limit to the size is that one needs to have a way to acquire its DNA.

Can the Animorphs morph germs?

KAA: In theory, yes. But there's no way to acquire one.
Scholastic.com - "According to K.A." October 1998

Can the animorphs morph single cell creatures? If so, why didn't they when they morph anything. Because germs are all over us.

KAA: You know, I've thought of this from time to time. The problem I have is how to "acquire" a germ. How do you know you're touching a particular germ? How do you focus on acquiring something you can't even see? If you figure it out, let me know.
Scholastic.com - "According to K.A." October 1998

I really enjoy your books, they are perfect for my busy schedule. (...) I remember you wondering how the Animorphs could morph bacteria. Well, if they ever wanted to, they could always press their fingers in agar in a petri dish. Within a couple days, colonies would form that they could touch.

KAA: You say you have a busy schedule and yet you found the time to consider the Truly Important Issue of morphing bacteria. Hmmm.
Scholastic.com - "According to K.A." January 1999

  • Wow, fantastic work finding those quotes!
    – Harris
    Commented Aug 28, 2017 at 17:55

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.