Does Terro Expire? (Here’s When You Should Replace It)

does terro expire

If you’re tired of having ants run rampant through your home and around your yard, then you’ve probably tried Terro ant killer at some point. Terro is a great, but an often asked question that many people have is does Terro expire? And if so, how often do I need to replace my Terro ant traps? 

Terro does not have a listed expiration date and technically will not expire. The liquid form of Terro will harden up over time and change color, losing its effectiveness against ants. You should replace Terro if you notice it has become hard, changed color, or is over 2 years old.

There’s a lot to know about Terro as well as all of its different uses. To learn more about how to use Terro best and if you need to replace it, continue reading, and we will take a deep dive into this potent ant-killer. 

This post contains affiliate links. This means Yard Blogger may earn a commission should you make a purchase using any of our links. Please refer to our full affiliate disclosure policy for full details.

Here’s a Quick Pro Tip!

Terro Multi-Surface Discreet Bait Stations (over at Amazon) work far better than the traditional Terro Liquid Ant Baits. These bait stations have an adhesive strip allowing you to easily stick them to walls and places where ants may enter.

It’s important to have multiple Terro Bait Stations spread out around your house. When ants invade your home, they usually enter from multiple points and not just one spot.

You need to make sure you can poison all the colonies simultaneously. Having multiple Terro Bait Stations is crucial to ensure you kill them all so they don’t return.

How Long Does Terro Liquid Ant Bait Last?

Terro ant bait can potentially last indefinitely until opened. Terro ant bait starts out as a clear liquid, but over time it may harden and turn into a brown or yellowish color. Once this happens, it is no longer effective against ants since crystalized Terro is harder for ants to eat.

You should replace Terro if you notice any of these signs that it has become hard or crystallized.

Do not keep Terro that has hardened, changed color, or is over 2 years old. Even though the liquid itself will not expire, you should replace dried-up ant bait since it is no longer effective against ants.

How Long Does Terro Last Once Opened?

Once opened Terro generally lasts 1-2 years before you need to replace it. This is assuming that you use it as directed, and do not place it in areas that are exposed to excess moisture or extreme temperatures.

Terro should be stored in a cool, dry place away from sunlight. Keep Terro away from children and pets since they may try to ingest it or cause a mess if it spills.

How Often Should I Replace Terro Ant Bait?

Terro ant bait should be replaced if it has changed colors, become crystalized, or you’re traps are empty. In general, if your Terro ant traps are more than two years old, you should replace them.

Observe your ant traps regularly to determine if they need replacement. If you notice that ants are no longer attracted to used Terro, then it has become ineffective and should be replaced.

Terro ant bait contains borax. The potency of borax doesn’t diminish with time and will remain deadly to ants forever. The texture and consistency of Terro are what matters the most. 

When Should I Replace My Terro?

In general, you should replace your Terro ant products after about 1-2 years in order to make sure your bait stations remain fresh.

While borax (the main active ingredient in Terro) doesn’t expire, Terro itself can become ineffective at killing ants once the liquid begins to thicken over time, or becomes crystallized. You may notice signs of this happening if your Terro starts turning brown or becomes hard to pour.

Why Does Terro Turn Brown?

Terro may turn brown due to the slow crystalization of the sugar within Terro ant poison. In addition to borax being the main active ingredient, sugar is also one of the main ingredients in Terro ant killer.

Sugar crystallization and browning usually occur whenever liquid Terro is exposed to warm temperatures or prolonged or air for long periods time periods.

You might also enjoy our post on Is Terro Toxic to Dogs, Cats, & Humans?

Does Terro Ant Bait Lose Its Potency? 

Terro ant bait is specifically designed and created never to lose its potency. The only active ingredient in Terro is borax, which is a highly stable chemical and doesn’t lose its ability to kill ants. For this reason, Terro ant bait doesn’t lose its potency and will be an ant killer always and forever. 

Is Terro Ant Bait Still Good if It Turns Brown?

If your Terro ant bait turns brown, it can still be used and has not necessarily gone bad. The bait’s color should be clear, however as long as it hasn’t hardened, the bait can be used. If your Terro ant bait turns yellow or brown, it only means that it’s been exposed to warm temperatures for too long. 

As long as the Terro is soft enough to be eaten by ants, it is ok to be used and hasn’t lost its potency. 

Can Terro Go Bad?

Terro can go bad if it has hardened, crystalized, or become too thick to pour. While Terro doesn’t have an expiration date, it loses its effectiveness when it has hardened. Liquid Terro that has hardened becomes unconsumable by ants, thus defeating the purpose.

Does Terro Evaporate? 

Terro ant killer does not evaporate if left exposed to the elements. While it may harden and ants will not have the ability to consume it, Terro does not evaporate. Additionally, when Terro is used outside, it is typically stored in weatherproof bait stations, further protecting against hardening and evaporation. 

How Do You Get Rid of Ants if Terro Doesn’t Work? 

If your Terro ant killer isn’t working to your satisfaction, you may be forced to try a new bait. Terro doesn’t expire and cannot lose its potency, but the ants in and around your home may simply be avoiding it. 

If this is the case, then trying out a different bait containing different ingredients may be necessary. If ants are avoiding your Terro bait, it is most likely because they are craving protein, while Terro is very sweet and contains sugar and water. 

Which Ant Bait is Most Effective? 

Terro ant bait is one of the most effective ant killers available to the general public. Terro is highly desirable for many reasons, and listed below are a few of them. 

Terro Takes Time to Kill

While some people might look at this as a downside, it’s a benefit. Because Terro doesn’t instantly kill an ant that comes in contact with it, the ant has time to take Terro back to its colony.

This aids in the spread of Terro throughout an entire colony rather than killing a single ant. 

Terro’s slow kill time also makes it possible to spread to the queen ant of the colony, thereby cutting the head off the snake. To destroy an entire colony may take up to a whole month with Terro, but its effect is lasting and sure.

Terro Is Not Toxic to Humans or Animals

The fact that Terro is not toxic to adults, children, cats, or dogs is beneficial for households with pets and small children.

Terro may irritate the skin and eyes or cause indigestion problems, but it isn’t deadly by any means. This fact alone makes Terro worthy of garnering the honors as a top ant killer. 

Terro Doesn’t Have to Be Replaced Too Often

Terro doesn’t have an expiration and therefore doesn’t need to be replaced unless it hardens. If Terro hardens and dries up, then it is unconsumable by ants.

Ants Ignoring Terro? This is Why

If you see that ants are avoiding Terro bait traps that you have set in and around your home, then there may be several reasons for this. 

Patience Is a Virtue 

Terro takes time to work and isn’t an instant killer of ants. Terro traps may also take up to a month to completely wipe out an ant colony.

Just because you constantly see ants near your Terro traps doesn’t mean that they aren’t working. There are thousands if not millions of ants to get rid of in any given colony, and these could be different ants each day. 

Place Your Bait in a Better Place

It’s essential to place your bait stations in areas readily accessible to ants and in places they travel regularly.

If you notice that there aren’t many ants around your bait station, it may be necessary to move your bait stations. 

Bad Storage Conditions

If you fail to store your Terro correctly, then the liquid form could dry up and harden. If this happens, ants will no longer be able to consume your Terro ant killer. 

Ants craving something different

Ants are tiny creatures that have instinctual cravings based on their needs. If you notice ants ignoring your Terro ant bait, it may be because they are craving protein or carbs instead of the sweet ingredients of Terro. 

Related Questions

Do Ant Traps Expire?

Depending on the type of ant traps that you have, they may expire. Terro ant traps, however, do not expire and will not lose their potency with time. 

Does Ant Powder Expire?

While ant powder doesn’t have an expiration date, most makers encourage replacing your ant powder every two years. 

Do Raid Ant Traps Expire?

Raid ant traps are similar to Terro ant traps in that they do not have a listed expiration date. Once again, it is encouraged that these be replaced as needed, but they don’t expire. 


Terro is a long-lasting and effective killer of ants and other tiny insects. If you take care of your Terro and store it properly, it will remain effective for as long as you have an ant problem.

Although it may take some time to destroy the entire colony, Terro will eventually solve your ant problem with significant effect. 

For more information about Terro and whether it’s safe to be used around pets and kids, visit the link below.

If you or another member of your household consumes Terro and you are worried, call the poison hotline at 1-800-222-1222 or visit their website at

If you want to restock or replace your Terro ant traps, Amazon has some great deals going on for their Terro Bait Stations

Similar Posts