Detecting mice early through monitoring is critical for managing numbers effectively, and reducing potential impacts on crops, feed and fodder and stored grain.
Monitoring can be carried out year-round, but generally the most important times to undertake monitoring are prior to sowing (March– April) and in early spring (September– October).
Observing and monitoring changes in populations so you can be familiar with what ‘normal’ levels of mouse activity are, is essential before any effective and targeted mouse control plan can be rolled out.
To help report and see what activity is like in your region, landholders can head to MouseAlert.
Mouse chew cards and active burrow counts are simple and effective techniques that can help show if mouse numbers are increasing in your paddocks.
Mouse Chew Cards
Mouse chew cards are most reliable when alternative food is scarce. They should be soaked in canola or linseed oil and set out in-paddock overnight. The proportion of the card that has been chewed by mice is recorded when it is collected the following day.
The GRDC has produced a chew card template and instructions that can be downloaded here.
Active Burrow Counts
To look for active burrows, walk a transect of 100 metres across the crop and count active holes in a 1-metre-wide strip. This gives an area assessed of 100 square metres, but should be repeated a number of times across the paddock.
Active holes can be identified by sprinkling talcum powder around holes and inspecting the level of disturbance the following morning.
The number of active burrows you find can then be used to estimate how many mice you may be dealing with. GRDC advises that if there are more than 2-3 active burrows per 100 metres, then you may have a problem with mice.
All the information above has been adapted from the GRDC’s Tips and Tactics: Better Mouse Management and Mouse Control website.
You can also discuss your situation with your local agronomist, who will be able to provide advice on mouse management.