Ants undermining garden wall

diystarter7

@shiraz99

100% agree see my above post.

Chickereeeee

Bait trap: "Very toxic to aquatic life with long lasting effects". Also "bait must be main source of food. Remove all other food sources". Not ideal. Would prefer a physical barrier if possible.

Silicon: flexible yes, but would it flow into gaps and grip in this environment? I guess I am looking for something pourable, that sets and remains flexible.

stuart45

Is the gap big enough to pour to grout in made from cement/fine sand and possibly a bit of SBR?

TELLIT01

Ants destroyed the cement between paving slabs in my garden so I would expect them to make short work of silicone sealant.

Vegastare

How about Diatomaceous earth it's a whitish grey powder and kills ants when they walk on it.  It is not a poison and not a danger to dogs/cats.  With the dust being fine like talc you would not need a windy day or maybe thinking of a way to push it into wall gaps.
Worth a google - must admit I also resort to bait stations and find them good but it can take a week maybe before the gritters get it back to the main nest.

Chickereeeee

Vegastare said:

How about Diatomaceous earth it's a whitish grey powder and kills ants when they walk on it.  It is not a poison and not a danger to dogs/cats.  With the dust being fine like talc you would not need a windy day or maybe thinking of a way to push it into wall gaps.
Worth a google - must admit I also resort to bait stations and find them good but it can take a week maybe before the gritters get it back to the main nest.

Interesting. I can imagine it working for a while, but outside subject to rain and dirt, I have doubts.

I will keep it in mind, but for now I think I will try bitumous paint: pour it into the cracks and see  what happens. 

Eldi_Dos

Lots of duct sealants have rodent and termite proof qualities, could see if they meet what you are looking for.

Cablecraft,black non hardening sealing putty.Usually needs to be kneaded to make pliable before use and use a spatula to press down into gap.

Filoseal+HD, the compound in that kit would do. Just brush some pavement dust over it to soften appearance.

Grenage

TELLIT01 said:

Ants destroyed the cement between paving slabs in my garden so I would expect them to make short work of silicone sealant.

Ants do not burrow through mortar, they simply use existing cracks and holes.

stuart45

I often find soil and ant nests in old stone garden walls when rebuilding them. A lot of the damage is done from the vegetation growing in the soil.
With the mortar being old, soft lime it was  probably easy for the ants to remove it. 
Can't remember seeing that sort of problem with brick walls built in cement mortar.