I was trying to think about the ole “what would shapeshifters do with their extra mass when they turn into something smaller” and I thought “maybe they just convert it all to energy” and then I thought “uh my guy that’s a lot of fucking energy”
massive explosion that fucks up everything in a pretty wide radius and at the epicenter there’s just a normal looking squirrel. the squirrel is unfazed
And when they want to turn back into a person: did I just see a squirrel eating an entire side of beef?
Animorphs answered this. It gets stored in another dimension that also happens to be the dimension faster-than-light spaceships move through so if you turn into a rat you carry a negligible but nonzero chance of having your extra mass being hit by a spaceship and resulting in Very Bad Consequences. See it all makes perfect scientific sense, no need for follow up questions.
Of all the risks of shapeshifting, suffering a hit-and-run from an intergalactic spaceship was not one I was expecting.
They blow up an alien continent in that book.