Ants killing young trees

[cotswoldcs]

Two years ago we planted some trees in a stewardship area on the farm. I went back last year and was disappointed that about a third of the trees had died. I noticed a large number of ant hills, some a foot or so tall and wondered if ants could have killed the young trees. I have since replaced most of the dead trees but don't want to suffer the same damage again. Has anyone else suffered similar damage? I searched the internet but found that whilst ants can kill young trees they can also do little harm (but I think this is generally saprophytic). Can I use an ant killer and if so when should I apply? A quick Google search has come up with ant killer powder but can't find anything bigger than 300ml and looks like it is aimed at the domestic/ household market.

 

[RushesToo]

I think there may be something more wrong than ants - you shouldn't be getting mounds a foot high - Are your neighbours, nearby fields?

Have you done something different and the ants had a bumper year, the food dried up and they ate the trees - maybe the trees were helped along with some nutrient that did more for ants than the tress?

 

[nick...]

Ive planted thousands of hedge and tree plants over the years and often find ants fill the spirals with soil but very few dead
Nick...

 

[Kidds]

Ants in trees usually indicate you have an aphid problem.
I would think it was the aphids doing the damage.