Winter Ant Control 

We tend to think of ants being active and annoying us only in the warmer months of the year, but ants can be a pest even in cold winter months.

Like other insects, ants are more active when their temperature is high (within limits*). So, in warm summer months, you are likely to have more problems with ants as they are more active and their colony numbers will be boosted by high breeding rates. In New Zealand winters activity will slow and breeding reduce or stop altogether.

However, there are some reasons why ants may still pester you in winter:

• In warmer northern parts of New Zealand temperatures do not often cause frosts and mean daytime temperatures will remain in the teens so that ants can remain active in these regions during the mild winters.
• In colder southern regions, such as Canterbury, even though there will be frosty nights when the temperature falls well below 0°C, these nights are frequently followed by bright sunny days. As ants live largely at ground level such as under pavers, the ground temperature can rapidly rise in the sunshine and warm the surface layer providing heat for ant activity. Even if the air temperature a metre above ground is still very low, the temperature on the ground may be high. It is common for ants to be seen in homes after a few sunny days in Canterbury winters.
• Ants are most often regarded as pests when they move indoors. In winter our homes and other buildings will be heated which provides ants nesting in the house, or close by, temperatures high enough to continue the activity.

How to Control Ants in Winter

In general, the method of control is still to follow the 1-2-3 Ant Control Programme. However, in winter, because the ants will not be producing many young they will not require protein food and will prefer sugary carbohydrate food for energy. So, I recommend using Kiwicare NO Ants Nest Killer Liquid Bait which is a high sugar bait. The high protein in NO Ants Nest Killer Gel Bait, although combined with sugars may be less palatable to ants in winter.

Parts 2 and 3 of the 1-2-3 programme can be particularly effective in winter when ant numbers are low and may help reduce ant numbers below their critical survival level so that the nest/s cannot recover in spring.

*In very high temperatures ants will reduce feeding activity and remain underground where temperatures are moderated.

David Brittain
Kiwicare