To allow our flora and fauna to thrive, it is crucial to control introduced predators such as possums and rats. However, controlling them can be a challenge across large areas such as farmlands and reserves.
Bait stations can be an effective option, especially during the initial ‘knockdown’ (high density) stage to remove high numbers of rodents or mustelids. Compared with trapping, the use of bait stations can save time, money and resources. However, if baits are misused there is a risk of poisoning non-target species including wildlife, livestock and pets. Some baits also build up in the environment (see below). It is recommended that you alternate baiting with trapping for ongoing control over large areas.
Below is an introduction to bait stations, a summary of baits used in New Zealand, and some safety tips. This information is intended as an overview, with no endorsements of individual products. It’s important to get region-specific advice from your council or DOC as to best practice, as well as obtaining any necessary permits.
- Where and how to use bait stations
- Safety advice for handling toxic baits
- Summary of baits
- Sources and further reading
Where and how to use bait stations
Bait stations keep baits fresh and prevent ground spillage, allowing predator species to access bait while restricting or minimising access by non-target species. The rule of thumb for placement is at least one bait station per hectare for possums, or two stations per hectare for rodents.
All baits should be secured in bait stations, out of reach of non-target species. Securing baits will also prevent predators from storing or caching the bait (rats in particular can store a lot of bait). On public land, stations should be placed at least 5 metres from walking tracks and clearly signposted (signs should remain even after baiting has finished, e.g. 12 months after final bait has been retrieved for Brodifacoum).
Stations should be regularly checked, with baits refreshed and old bait safely disposed of (for best practice, refer to the product label). Keep a record of your bait stations, as well as which baits you’ve used and when.
The type of bait station depends on the site, which bait you use, the risk of the bait to non-target species, and whether the station is on private or public property. Commonly-used bait stations are available from Philproof, Key Industries and Pest Control Research, among others. See our guide on where to buy equipment.
Pulsing is recommended when using baits. Instead of baiting year-round, putting bait out at key times (or pulsing) is more strategic and also cheaper. Effective pulsing times are usually four times a year (August, November, January and April). Follow the product label for recommended dosages and station filling/refiling times.
Make sure grass is controlled at least one metre from bait station entrances. This prevents bait from going mouldy and also makes access easier for your target species.
Safety advice for handling toxic baits
- Know your area, including which non-target species are at risk of secondary poisoning – e.g. people, dogs, livestock, and native birds such as weka.
- Learn when to use baits most effectively, e.g. rat control is best just before or during bird breeding season (usually Aug-Jan).
- Read the product label carefully, as well as the manufacturer’s instructions and Safety Data Sheet.
- Use thick rubber gloves when handling toxins (and also when handling dead animals to avoid leptospirosis).
- Check that no toxins have spilled on the ground when refreshing bait.
- If poisoning is suspected, contact a vet/doctor immediately or call the National Poisons Centre on 0800 764 766 (0800 POISON).
- Most poisons have antidotes but they must be administered in the early stages by a doctor/vet.
- Check whether you need a Controlled Substance Licence (CSL) and any other approval prior to use.
- If unsure, contact the manufacturer or biosecurity department of your council.
Summary of baits
We have written an at-a-glance summary of baits available in New Zealand with details about each bait.
Sources and further reading
- Northland Pest Control Guidelines by Landcare Trust.
- DOC’s Vertebrate Pesticide Toxicology Manual (PDF 1, PDF 2, PDF 3, PDF 4, PDF 5).
- Auckland Council’s Pest animal control guidelines for the Auckland region.
- Landcare Research — Manaaki Whenua’s Vertebrate Pest Control Decision Support System.
- DOC’s site specific factors for predator control.
- Private Landowners’ Guide to Possum Control by National Pest Control Agencies.