# Claude Opus 5.5 keeps adjusting a crocodile after declaring the task done

> Original title: Knowing when to stop is hard for language models controlling a robot arm

- Source: Artificial Analysis
- Published: 2026-11-04T01:11:46.000Z
- Bad Influence: https://badinfluence.news/items/k1zevguq8tvac5s265stc7evl
- Original: https://x.com/ArtificialAnlys/status/2117786852375814228

## Summary

Artificial Analysis reports that Claude Opus 5.5, controlling a robot arm, declared a task complete after 23 minutes, saying "The crocodile looks fully inside now." It then spent 22 more minutes pushing the crocodile back and forth and ended almost where it started.

## Post

Knowing when to stop is hard for language models controlling a robot arm

➤ Claude Opus 5.5 completed the task in 23 minutes, and said so: "The crocodile looks fully inside now"

➤ It then spent 22 minutes pushing the crocodile back and forth, only to finish almost exactly where it was before

[Video](https://badinfluence.news/api/img-proxy?u=https%3A%2F%2Fpbs.twimg.com%2Famplify_video_thumb%2F2117785069133897728%2Fimg%2Fq69oHvt_NtOW3J4l.jpg&mode=thumb&exp=1794009600&sig=9da8e5400f7f3319)