91É«ÇéƬ

Earth’s north magnetic pole is moving from Canada towards Siberia. Has there been a noticeable effect on migrating animals that sense the geomagnetic field as a navigation aid?

Bob Werner,

Pasadena, California, US

Why is it harder to remove a crease from a shirt with an iron than to put one in?

Matthew Bradby,

London, UK

To answer this question – or ask a new one – email lastword@newscientist.com.

Questions should be scientific enquiries about everyday phenomena, and both questions and answers should be concise. We reserve the right to edit items for clarity and style. Please include a postal address, daytime telephone number and email address.

91É«ÇéƬ retains total editorial control over the published content and reserves all rights to reuse question and answer material that has been submitted by readers in any medium or in any format.

Terms and conditions apply.