3-LS2-1: How Living in Groups Helps Animals Survive
Also called NGSS 3-LS2-1 · Topic: Interdependent Relationships in Ecosystems: Environmental Impacts on Organisms · Life Science
The Official Wording
Construct an argument that some animals form groups that help members survive.
NGSS Lead States, 2013 · Read it on nextgenscience.org · checked October 15, 2026
What 3-LS2-1 Means in Plain English
Third graders build an argument, with a claim and evidence, that living in a group helps some animals stay alive. They look at examples like wolves hunting together, fish swimming in schools and meerkats taking turns keeping watch, and explain how each member benefits.
The focus is on the benefits of groups, such as finding food, defending against predators and coping with weather, not on every animal living this way. It builds on 1-LS1-2 animal families and leads to 3-LS4-3 on how habitats support survival.
3-LS2-1 I Can Statements
- I can name animals that live in groups.
- I can explain how a group helps its members survive.
- I can back up my claim with evidence.
3-LS2-1 Worked Example
A playground game that turns prairie dog lookouts into evidence for an argument.
Do feeding animals get caught less often when one of the group stands guard?
Set It Up: Paper squares scattered on the grass as food, one student playing a coyote, and a group of students playing prairie dogs.
- Round 1: prairie dogs gather paper squares with eyes down while the coyote sneaks in.No lookout
- Count how many prairie dogs the coyote tags in one minute.Round 1: 6 tagged
- Round 2: one prairie dog stands as a lookout and claps when the coyote moves.Clap, all run to base
- Count the tags again.Round 2: 2 tagged
- Play each kind of round twice more and compare the totals.Lookout rounds: fewer tags each time
Prairie dogs with a lookout were tagged far less often than prairie dogs feeding with no warning.
Why it works: Real prairie dogs give sharp barks when a hawk or coyote comes near, so the whole colony hears about a threat that heads-down feeders would miss.
Common Mistakes with 3-LS2-1
Giving a claim with no evidence
“Wolves live in packs because they like each other.”
Try this: Ask what the group does that one wolf cannot, like bringing down large prey together, and use that as evidence.
Saying all animals live in groups
“Every animal needs a group.”
Try this: Compare with animals that mostly live alone, like tigers and most bears. Groups help some animals, not all of them.
Treating a game as proof about real animals
“Our game shows prairie dogs always survive.”
Try this: Pair the game with facts about real prairie dogs, like their alarm calls, so the argument rests on true animal behavior.
Where 3-LS2-1 Fits
Practice 3-LS2-1
Quick Check
- How does swimming in a school help a small fish?
- Why do wolves hunt in a pack?
- Emperor penguins huddle in winter. How does that help them?