How Animals Digest Food

About this printable How Animals Digest Food science reading passage, NGSS-aligned (Grades 3-5)

This Grade 4 science reading passage explains how animals digest food and aligns with NGSS standard 4-LS1-1. Students discover how the digestive system breaks down food into tiny pieces called nutrients that the body uses for energy and growth. The passage describes the journey of food through the mouth, stomach, and intestines, explaining how acids break food apart and how nutrients are absorbed into the blood. Students also learn that different animals have different digestive structures depending on what they eat—cows have four stomach chambers for digesting grass, while birds have a gizzard to grind food. This audio-integrated resource includes a simplified differentiated version, Spanish translations, interactive multiple-choice questions, writing activities, and graphic organizers. The materials help students build foundational understanding of animal structures and functions through accessible, grade-appropriate language and real-world examples that connect to the NGSS Disciplinary Core Idea LS1.A: Structure and Function.

Written by Workybooks TeamPublished by Workybooks

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Sample passage and quiz from How Animals Digest Food

Human digestion diagram. — How food turns into energy.

Digestion is the process of breaking down food into tiny pieces that the body can use. Animals need digestion because the body cannot use whole pieces of food for energy and growth. The food must be broken into very small parts called nutrients that can travel through the blood to all parts of the body.

When you eat, food enters your mouth first. Your teeth chew the food into smaller pieces, and saliva makes it wet and easier to swallow. The food then travels down a tube into your stomach. The stomach is like a muscular bag that squeezes the food and mixes it with special liquids called acids. These acids break the food into even tinier pieces.

After the stomach, the food moves into long tubes called intestines. In the intestines, nutrients from the food are absorbed into the blood. The blood carries these nutrients to every cell in your body so you can grow, move, and think. Whatever the body cannot use becomes waste and leaves the body.

Different animals have digestive systems that match what they eat. Cows eat grass, which is hard to digest, so they have four stomach chambers to break it down completely. Birds do not have teeth, so they have a special organ called a gizzard that grinds food into small pieces.

Interesting Fact: A cow's digestive system is so powerful that it can turn grass into milk! The nutrients from grass travel through all four stomach chambers before being absorbed into the cow's blood.