The Terro PCO Ant Bait Stations do not really have an expiration date because the effectiveness of the active ingredient does not diminish over time. However, like any food-based product, the bait may become less appetizing to foraging ants after an extended shelf life. We recommend using fresh bait if you've had the same stations for more than two years.
Once ants consume the Terro PCO Ant Bait it starts working almost immediately to kill them. You should see results within 1-3 days from when the ants feed off the bait.
Once a colony of ants die from the Terro PCO Ant Bait Stations - 30 stations, the larvae would die from lack of care from the workers/adults.
We would not recommend placing Terro PCO Ant Bait Stations outside while you are still experiencing freezing temperatures. You can place them indoors near ant trails or where you are seeing ant activity if you wish.
The Terro PCO Ant Bait Stations should be protected from rain when placed outside.