In our latest Pest Pulse survey we asked pest managers to name their go-to products and preferred actives when it comes to rodent control.
Pest managers are always curious about which products others are using, so as we enter the rodent season, Pest Pulse turns the focus on rodent control.
There is a wide range of rodent baits on the market. Not only are a number of rodenticide active ingredients being used, but there is also a variety of product formats. Not surprisingly the two most commonly used bait formats are wax blocks and soft baits (Figure 1). The vast majority of pest managers are using more than one product format – most often using both wax blocks and soft baits as part of their toolkit – as well as liquids, pellets and powders on occasion.
In terms of the decision-making process, when choosing a bait for a particular job, pest managers are considering a number of factors. The top three factors influencing choice of bait are palatability, safety and speed of performance (Figure 2). Price/value, bait format, active ingredient and brand are the secondary considerations for most pest managers. This makes sense, as palatability is key to achieving the initial feed which then flows on to speed of performance, and of course, with the risks associated with rodenticide use, it’s good to see safety is a priority.
This is reflected when carrying out rodent control in sensitive areas, when pest managers are either using lockable bait stations or alternative control techniques. However, in roof voids, a wide variety of bait placement techniques are used, with over a third of pest managers placing the bait loose in the roof void (Figure 3). In sub-floors the use of lockable bait stations increases significantly, although still over 10% of pest managers are using loose baits.
The use of lockable bait stations is the best practice for most situations. Fixing the baits firmly in place allows for accurate monitoring and is aimed at preventing rats hoarding the bait. When rats move the bait, the chance of accidental exposure increases. Nails or zip ties are better than nothing, but this does not prevent chunks of bait being removed and does not eliminate the risk of exposure to native animals, such as possums.
In choosing bait products, pest managers will often select different products depending on whether the bait is being used to clear out an infestation or being used as part of a maintenance program. Not surprisingly, pest managers have a wide range of preferred baits, although it is quite clear that for maintenance treatments wax blocks are the preferred product type (approx. 85%). With clear out treatments, the split between soft baits and blocks is more even, with 45% stating a soft bait as their preferred product and 55% preferring a wax block.
When considering the performance of the active alone (Figure 4), just over a third of pest managers believe brodifacoum (36%) provides the best performance, followed by difethialone (23%) and bromadialone (13%). In situations when pest managers want to decrease the risk to non-target animals, bromadialone (16%), difenacoum and coumatetralyl (both 12%) are preferred. The number of pest managers preferring brodifacoum dropped (to 23%), indicating that a number of pest managers are indeed considering active ingredient potency when there is an increased risk of non-target exposure.
Of course in sensitive areas, many pest managers also use a range of alternatives to baits such as snap traps (67%), glueboards (54%) and live traps (40%). The most popular attractant used in traps by pest managers was peanut butter – being the preferred lure for over 50% of respondents. Interestingly, around a third of pest managers also used additional attractants with bait stations, with peanut butter again the most popular choice.
In terms of measuring the success of treatments and identifying the areas of activity, it was encouraging to see over 50% of respondents used monitoring baits. Additionally, nearly 60% of pest managers offer rodent-proofing services to implement their recommended preventative measures.