By Albert Makendenge
A well-defined biosecurity plan of action for any farm set up has got to include a way of dealing with rodents that may directly or indirectly cause damage to crops. While poison baits have been the most commonly used method in the past, they have recently come under increasing scrutiny over their potential effect on non-target species. Therefore below are the top ten recommended tips for controlling rodents at a farm.
- Minimize the attractiveness of the farm environment. Such an environment is more likely to be more appealing for rodents. You can do this by tidying up the farmyard and removing any shrubbery, long grass, old machinery and general debris, ideally within a 30m radius of farm buildings.
- As a second line of defense against the agility of these creatures, close all holes and possible points of entry such as where pipes pass through a wall and eliminate openings around doors and windows. Guards on downpipes and screens on grilles and airways will also help.
- Remove debris that rodents can use for nesting, such as piles of wood, piping, rubble and old equipment. It can also help to minimize availability of water near farm buildings such as ponds, ditches and stagnant pools.
- Feed stores need to be secure, well maintained and kept as rodent-proof as possible. If telltale droppings are found, action is needed.
- Set a planned approach to baiting control programmes, which should have a start, middle and end. This may take as few as 14 days and usually no more than five weeks to clear a rodent colony, depending on the severity of infestation.
- Proprietary bait stations can be ineffective, given the natural wariness of rodents, so create bait stations from materials already found in their environment.
- Cold, shiny plastic boxes with at least one right-angle turn and mostly too small to sit up in and to eat in a group will not attract rodents. Instead, use familiar, readily available farmyard materials such as corrugated iron, wooden sheeting, pallets, slates, tiles, bricks, blocks and old tyres.
- Robust construction and small enough entry points to deny dog access are important. Sturdy wooden trays around 150 * 76 mm make good bait containers, protected by an immovable structure with an entry height of about 76 mm and an internal height of 150 to 200 mm.
- Wooden or corrugated-iron sheets propped up at a shallow angle against walls and weighted down with bricks also work. As do pallets raised up on bricks, blocks or old fence posts and securely covered with sheeting. The same goes for loose stacks of bricks or blocks roofed with old tiles or slates.
Applying these methods can help to minimize rodent infestations and reduce the need to use poisonous rodent traps.