How long does it take for roach killer gel to work?

You could start seeing dead roaches within a matter of hours, and should start to see significant results within a week. After a month, over 90% of roaches could be dead. At that point, you’ll see very few emerging from hiding. Still, you should continue to apply tiny drops of gel bait until you stop seeing roach activity.

How do I know if the roach bait is working?

The number one sign is fewer cockroaches out in the open. You should also find fewer droppings (if that’s been a problem).

Remember to keep an eye on the bait. At first, if it’s disappearing quickly, that’s a good sign—the roaches are taking it and it should be doing its job. Later, as it kills the pests, you should find more left over when it’s time to reapply.