How to Use Chalk for Ant Prevention

A line of colored chalk might appear to block ants, but it is only temporary.

Using chalk to prevent ants can be done with regular blackboard chalk or with special "ant clalk" that contains insecticides. How they work seems to be contradictory. People use regular blackboard chalk because they believe that ants won't cross the chalk line. But ant chalk is designed to poison the ants when they cross the line. Which one is correct? Blackboard chalk may work temporarily if it disrupts an ant's scent trail; it is ineffective as an ant preventative, according to Barb Org, an extension educator with the University of Lancaster. Ant chalk, however, is a better solution because if it doesn't prevent ants from entering, it will kill the ants within a few minutes.

Things You'll Need

• Ant chalk that contains insecticide

Instructions

1. Purchase ant chalk that is registered with the EPA. Do not use imported ant chalks because they may contain deltamethrin and others cypermethrins that cause health problems.

2. Do not use ant chalk in combination with ant baits. You don't want the ant to cross the line and be killed before they can take the ant bait back to the nest.

3. Clean the area thoroughly to remove any food or water sources that might attract the ants. Keep food and trash in secure containers.

4. Draw a line across the area you want to prevent ants from crossing or in areas where you have seen the insects. The line should be continuous and completely block any routes the ants might take.

5. Replace the line as directed on the package or whenever it seems to fade.

Tips & Warnings

• Keep the chalk out of reach of children when not in use. Children may mistake it for regular chalk.

References

• University of Nebraska---Lancaster; Controlling Pests with Home Remedies; Barb Org
• University of Pittsburgh Cancer Institute Center for Environmental Oncology; Limit Pesticide Use
• National Pesticide Information Center; Illegal Insect-killing Chalk