Types of Rodenticide

Different Poison Boxes

What type of poison is best for rodent control?
And why do we not sell block bait on this site?

To Begin, the table below gives the high-level comparison of the different types of bait, with more details in the text below. It is the top two rows that are the most important when dealing with rodent infestation: how palatable the bait is to rodents and the likelihood of them consuming a lethal dose in a single feed.

Paste Grain Block
Palatable to Rodents Very High High Low
Lethal (Single Feed) High High Low
Risk of Spilage Yes No No
Use in Wet Conditions No Yes Yes
Pet Safe No No Better

Grain Bait

This bait is made from wheat grains and is very close to the rodent’s natural food source. It is therefore highly palatable and the likelihood that it consumes a lethal dose in a single feed is also high. Plus, it is easy for a rodent to transport to their food store thereby poisoning others as well.

On the down side it is prone to spillage with a risk of poisoning other mammals. It will also go off very quickly if it gets wet.

Paste Bait

This is very similar to a rodent’s natural food source but not as close as grain bait. However, it is certainly palatable and still likely that a rodent will consume a lethal dose in a single feed. Unlike grain bait, paste is not prone to spillage and continues to perform well in wet conditions.

Similar to grain bait, paste is still palatable to other mammals, including pets, so needs to be used with care.

Block Bait

Block bait is generally not palatable to pets and is therefore sold as a ‘pet safe’ product. However, it is also far removed from a rodent’s natural food source and is therefore not very palatable to them either. Consequently, they are unlikely to consume a lethal dose.

A further problem if used outside is that slugs love it and will very quickly finish off whatever you put in the bait station. Although maybe this could distract them from your vegetable patch.


What is the point of laying bait if the rat or mouse won’t eat enough to consume a lethal dose? No matter how safe it is for pets, block bait is really a non-starter for realistic pest control.

So, you really need to choose between grain and paste bait, or in my experience, the best is to use both. However, you need to be careful, particularly if you have pets in or around your home.

For safe and effective rodent control follow our ‘how-to’ guides. Inside the home make sure the bait is laid only in areas that pets cannot access: attic, garage, basement, cupboards. If you need to lay bait in ‘open areas’ then make sure pets (and children) are kept clear for the duration.

For rats outside, always use a bait station.  Bait should then be secured using the internal metal skewer so that it can’t be removed and spread around your garden.

If you have any other questions with regards to which bait is best for your particular situation, please contact us at: info@diypestsupplies.co.uk