RISING MOUSE REPORTS IN WA A REMINDER TO STAY VIGILANT AHEAD OF SEEDING

Recent reports from Western Australia of increasing mouse activity, as outlined in the CSIRO mouse updates, prompted Grain Producers Australia (GPA) to share the following column in rural media around the country earlier this month.

Since its release, we’ve spoken with CSIRO Research Officer Steve Henry, who has just returned from WA where he was ground truthing the reports and holding grower education sessions about mouse management.

Steve's observations confirming reports and the discussion is featured in a new GPA podcast episode which builds on the observations outlined below, adding further context on monitoring, early indicators and how growers can prepare if conditions begin to shift.

Listen here

By GPA Research Development and Extension Spokesperson Andrew Weidemann.

Reports emerging from Western Australia in recent weeks should have grain growers across the country on high alert as preparations for seeding gather pace.

This warning comes as grain producers are already dealing with increasing uncertainty about fuel and fertiliser access due to escalating global conflict affecting trade routes. 

Growers around Geraldton and Ravensthorpe have been sharing photos and short videos showing mice moving through paddocks and stubbles ahead of the coming season. These are firsthand observations from growers on the ground and, while it is too early to draw conclusions about how widespread the issue may become, the level of activity being reported has clearly raised concern.

Across South Australia, mouse activity has already been present in some areas for some time and many growers have been keeping a close eye on numbers through summer. What has sharpened attention recently is the emergence of these reports from Western Australia, particularly from districts where growers may not have expected to see activity building this early.

Mouse populations can escalate rapidly. In most seasons numbers remain at background levels and cause little disruption. But when conditions allow populations to build without being noticed, the situation can change quickly. The early indicators are usually present well before crops are sown, which is why the weeks leading into seeding are such an important time to be paying attention.

The reports now circulating from Western Australia highlight how valuable on-farm observations can be. In many cases, growers have picked up the activity simply because they have taken the time to walk paddocks and look closely at what is happening beneath the stubble.

Monitoring for mice does not need to be complicated, but it does require growers to spend some time physically inspecting paddocks rather than assuming any problem will reveal itself later. Fresh burrows are often the clearest indicator. Walking paddocks and looking for active holes, particularly in areas where grain remains on the ground following harvest, can quickly reveal whether mice are present.

Some growers are also using chew cards to confirm feeding activity, while others check paddocks after dark when mice are most active and easier to detect moving through stubble. These sorts of checks help build a clearer picture of whether numbers are sitting at background levels or beginning to increase.

CSIRO is expected to release updated mouse monitoring and outlook information in the coming days, and growers should keep an eye on that advice as it provides a broader picture of conditions and population trends across the cropping regions.

National monitoring programs provide valuable guidance, but they can only ever form part of the story. The reports currently circulating from Geraldton and Ravensthorpe have come directly from growers sharing what they are seeing in their own paddocks, which is often the earliest signal that mouse numbers may be changing.

If monitoring confirms mice are present, growers should also be thinking about how they will respond.

Experience from previous seasons has consistently shown that baiting is most effective when it is done at sowing when other food sources are low and applied consistently before mouse populations expand. Once crops are established and numbers have already increased, the scale of the problem becomes much harder to manage.

Planning bait access early is therefore an important step. In seasons where mouse numbers increase across multiple regions, demand for bait can rise quickly and supplies can tighten just as growers are trying to respond. Ensuring bait is available on farm allows growers to act immediately if monitoring shows numbers increasing.

Ensuring growers have access to effective control tools is also an important part of industry preparedness. Grain Producers Australia continues to work closely with the CSIRO, the Grains Research and Development Corporation and other partners to help ensure growers receive timely and practical information as conditions develop.

GPA is also continuing to work with the Australian Pesticides and Veterinary Medicines Authority, GRDC and CSIRO to address data gaps in research and ensure permits can be made available for zinc phosphide bait products such as ZP50. Maintaining access to these tools is critical in seasons where mouse numbers rise quickly and growers need to respond without delay.

As the situation becomes clearer over the coming weeks, ensuring growers have both the information and the tools they need to manage mice will remain front of mind.

For now, the reports emerging from Western Australia serve as a timely reminder that mouse populations can begin to build rapidly in the lead up to seeding starts. Taking the time to check paddocks, follow the latest monitoring information and ensure bait is available if it is needed will place growers in the strongest position to respond if numbers increase as the season approaches.

This article was first published by Farm Online on March 26, 2026 HERE