Using Fewer Animals in Science Can Mean Better Science

A leading science journal called Nature Biomedical Engineering has sent a clear message to researchers around the world: using more animals in an experiment does not make the science stronger. The journal's editors say that what really matters is asking the right question and planning the study carefully. They want scientists to use the smallest number of animals needed to get a clear, honest answer.

For a long time, some researchers believed that adding more animals, more groups, and more species to a study would make their work look more impressive to journals. The editors say this thinking is wrong. They explain that piling on extra animals mistakes size for quality, and that a big study is not the same as a good study.

The journal's editors say every animal experiment should start with a clear scientific question, not with a decision about how many animals to use. Once scientists know exactly what they are trying to find out, they can choose the smallest and most careful experiment that will answer that question. When researchers do this honestly, the study almost always turns out better — for science, for ethics, and for publication.

The editors also point out that there are times when larger animals are truly needed. For example, a device meant to repair a human-sized heart valve cannot be properly tested in a tiny mouse. In those cases, using a bigger animal is the right call because the science requires it, not just because it looks impressive.

Scientists are also encouraged to think about other tools that can replace or reduce animal use. Methods like computer models, lab-grown human organoids, and miniature organ systems can help answer questions about how something works inside the body. These tools can sometimes give strong evidence without needing extra groups of live animals.

Animal welfare is another big part of this issue. The journal expects researchers to watch their animals closely for signs of pain or stress, to use pain relief when needed, and to end experiments humanely as soon as possible. Researchers should also ask whether every test group in their study is truly necessary before adding it.

Reviewers — the expert scientists who check studies before they are published — also share this responsibility. The journal says reviewers should not automatically ask for more animal experiments when they review a paper. They should only request extra animal work when it is absolutely needed to support a specific claim.

The journal's editors ended with an encouraging note: scientists who plan carefully and choose their models wisely will always find a welcoming home for their work at Nature Biomedical Engineering. Good science is not about how many animals are in a study — it is about how well the study answers the question it set out to ask. Fewer animals, chosen wisely and studied carefully, signal better science.