Passage Summary: Some groups of animals do great and live everywhere, while others shrink and become endangered. Since ants as a whole are incredibly widespread and successful, the author thinks every single type of ant must be safe.

Conclusion: There are no individual ant species currently at risk of extinction.

Reasoning: Ants as a group are the most successful type of insect and are found in almost every environment on Earth.

Analysis: This argument suffers from a classic whole-to-part error. Just because the class of ants is thriving globally doesn't mean every specific species within that class is doing well. The author assumes that the success of the group as a whole guarantees the safety of every individual member. Look for an answer that points out this failure to account for specific, isolated species that might be struggling despite the general success of ants.