It has been pointed out in other reviews of this book that the title is really a little off and slightly misleading - there are more than "Animals" in this "visual encyclopedia of life on Earth," which, come to think of it, would make a better title here than subtitle. This is a small issue, perhaps, but still annoying as this is clearly aimed at kids who, if young enough, may have a hard enough time distinguishing that not everything that is alive is an animal or that more things than animals are alive.
I also have a couple of issues with the layout:
First off, the arraignment of the photos on the collage pages is, to my eyes, overstuffed. While it is nice to show the great variety of species and subspecies of a given animal, some of the pages are visual cacophony and many (physically) smaller species get short shrift - their photos are so small as to be difficult to distinguish their features, making them seem almost generic, their details indiscernible. Like many DK books, the vast majority of photos are cropped completely around the animals (or fungi, etc.) and placed against a plain white background, removing the living thing completely from its environment - something of a weakness for me in this context.
Second - the species names swirled around their photos, some numbered, some not (the numbers refer the reader to the text below, which I'll get to below) adds to the visual noise. Again, the layout in most DK books (I'm thinking the Eyewitness series off hand) is not too different, but here there is a sense of trying to jam too much into the space.
Lastly, the text, which mostly runs in a banner across the bottoms of the pages, is small and stuffed into a solid block without even paragraph indentations to break it up. It does include the circled number for the animal it refers to, but especially younger readers may well have issues with finding and deciphering the information they want.
Of course, like most DK books, the photography here is terrific and occasionally stunning. The text, without having read every word, appears to be accurate and digestible by most readers above a second-grade level (thought it seems aimed a bit higher). This is a decent general reference for elementary-aged kids and animal (and other living thing) lovers among them will certainly enjoy the array of life on display here in lush photography. But anyone doing a serious report, for instance, above the 2nd or 3rd grad level, will likely need to go beyond this into something with more detail about the given / desired subject.