Davies considers the physics of anatomical structures, comparing humans' capabilities to those of smaller animals such as flies and geckos; the discussion then turns to what happens on the cellular level. Layton's cartoon illustrations are an excellent complement to the text, assisting in the visualization of the mathematical relationships and also adding humor with anthropomorphized animals and cells. Glos., ind.

With yet another fresh angle on the life sciences (Extreme Animals, rev. 1/07; What's Eating You?, rev. 1/08), Davies considers the physics of anatomical structures by explaining the mathematical relationships among the properties of length, surface area, cross section, volume, weight, and strength. She compares human capabilities to those of animals such as flies, water striders, and geckos in order to show how smaller organisms -- with smaller measurements -- are capable of feats that larger animals cannot manage. (And using what she calls the "Big Thing, Little Thing" rule -- "If you double the length of something, its surface area and cross section go up four times, while its volume and weight go up eight times" -- she explains why it's impossible for car-sized spiders and other such monsters to exist.) The discussion then turns to what happens on the cellular level within larger bodies, which require more complex structures with large surface areas in order to accomplish basic functions such as respiration and locomotion. Layton's cartoon illustrations are an excellent complement to the text, assisting in the visualization of the mathematical relationships and also adding humor with anthropomorphized animals and cells. A glossary -- as accessibly written as the main text -- and an index conclude the book.

The pair behind such child-friendly explorations as Poop and What's Eating You? (2004, 2007) deliver a similarly windily subtitled discussion of size in the animal kingdom. The pair begins by describing how the doubling of a creature's length increases its surface area and cross-section (and therefore muscle power) by a factor of four and its weight and volume by a factor of eight--leading to such conclusions as, "That's how ants can be stronger than humans!" They go on to explore how increasing the size of a creature necessitates increasing complexity, explaining how single-celled organisms can get by with osmosis but mammals require respiratory and digestive systems. The tongue-in-cheek tone, concrete examples and Layton's undeniably appealing cartoons will go a long way with kids, as will the compact trim and one-topic-per-spread organization. But as a science book, it flirts with oversimplification. While evolution is mentioned multiple times, for instance, the concept of survival of the fittest is given short shrift, leaving unqualified such teleological assertions that gibbons attained their modern, house-cat size because "having a nice, light little body was very useful." A shame. (Nonfiction. 8-12)

This book explains the reasons why big animals (humans and other mammals) are not capable of climbing walls, flying, or lifting heavy items, but why little animals (amphibians, birds, and insects) are able to. The BTLT (Big Thing Little Thing) Rule explains it all: if you double the length of something, its surface areas and cross-section go up four times, while its volume and weight go up eight times. This book is wonderfully illustrated and contains a glossary of the scientific terms referenced in the book. Recommended. Teresa Raimo, Media Specialist, Ridgefield Park (New Jersey) School District

This witty and informative book uses the "Big Thing, Little Thing" rule (which explains how the length, surface area and cross section of an object or creature are relative to its volume and weight-thus, there are no "car-sized spiders") to explore how size affects living things. Davies's often humorous text and Layton's energetic illustrations demonstrate why humans don't have superpowers ("we'd need toes tens of thousands of times bigger than a gecko's to hold us on the ceiling"), and later spreads discuss the advantages and limitations of being very small or very big ("Small animals have a bigger outer surface area for their volume than big animals, so they have trouble keeping warm"). The spot-on comic delivery and readily comprehensible explanations make this a prime pick for readers curious about physical science in the natural world. Ages 8-up. (July) Copyright 2009 Reed Business Information.

Gr 4-8-This unique title uses geometry to discuss the varying strengths and capabilities of different animals. In a chatty tone, Davies starts off by describing the strict rules that control what bodies can and cannot do. She goes on to explain how the strongest animals are much smaller than humans. "Some important features of bodies-like how much food and air they need-depend on volume and weight. Others-like the strength of muscles-depend on cross section or surface area." This is the basis for the BTLT (Big Thing, Little Thing) Rule: "If you DOUBLE the length of something, its surface area and cross section go up FOUR times, while its volume and weight go up EIGHT times!" BTLT is used throughout to explain why humans cannot fly, yet Arctic terns can travel 20,000 miles every year from pole to pole and back again. Humans cannot lift buses, but the rhinoceros beetle can lift 850 times its own weight. The author uses clear language and engaging examples throughout. Cartoon illustrations add humor and clarity to the book. A handy introduction to animal sizes.-Anne Chapman Callaghan, Racine Public Library, WI Copyright 2009 Reed Business Information.