Stacking wood against a live tree?

I usually just stack my split wood on pressure treated wood on top of cinder blocks with 2x4's on each end. When I just started a new stack, there was a live tree right there to support the end of the stack, so I used it as an end support. Not sure if it's just my 'magination, but it seems like I have more big black ants in this stack than usual. Could that be because of the live tree?
Hopefully the ants find a new home as the wood dries out.

 

Probably they were in the neighborhood and are inspecting that fresh wet wood. They’ll leave again

 

Ants may be inside the tree and/or using it to get to the upper part of the tree to feed. As long as the stacks are off the ground and mostly dry i wouldnt worry about them. Stacking against trees has been done since man started stacking wood. The only drawback is the tree swaying and the stack falling/shifting.

Some real nice looking stacks and shed btw!

 

There is a bit of wear and tear on the tree's bark.

I also stack between trees, however.

 

Big black ants could be carpenter ants. The tree stacked against could be the host for them as well as any tree near could be. Carpenter ants ( and some other ants) harvest honeydew from aphids and other bugs ( some they chew the wings off so they can't fly away ) so they could be all the way up the top of that tree doing their thing with their "cows". Or the tree(s) nearby.