Do you have a photo you can share of the damage? Some holes are created by Yellow-Bellied Sapsucker woodpeckers (and often are harmless, even when extensive) while others might be the work of a type of wood-boring insect (often beetles, but not always). There is no insecticide that can treat beetles already inside the wood, but a certified arborist with diagnostic experience can help narrow-down the possibilities and check on the health of the tree. If insect borers are present, often the tree was first stressed by an environmental factor (drought, saturated roots, girdling roots, etc.) that predisposed it to attack and made the insects attracted to it. If the holes are in fairly even, horizontal rows, the woodpecker is the likely culprit, and they migrate out of the area in spring. You can find examples of the two styles of bark holes they create in the linked page above.

Miri

We did receive the photo, yes. That is a millipede, so it didn't bore into the wood (they can't chew into live, intact wood), but merely explored the resource after something else created a hole. Millipedes eat dead and decaying vegetation, primarily fallen old leaves and old plant stems. They seek darkness and moist areas, so if any holes in the tree are affected by wood decay, that would explain its presence. Sap oozes from Yellow-Bellied Sapsucker wells also, and that too could attract them. If you can share photos of the trunk damage and what the suspected borer holes look like, we can help determine if they are indeed due to insect invasion or the woodpecker.

Miri

Thank you for the additional photos. It's hard to see enough of an overall pattern from this close distance, but they might be sapsucker holes, in which case there shouldn't need to be any cause for concern. (You noted they don't have the pattern visible in the woodpecker gallery we shared, but we've seen instances where holes are pecked with more distance between them and the rows are less distinct, perhaps because the bird was interrupted or gave up to choose another tree.) It might not hurt to have the tree assessed by a certified arborist, although they might not be able to make a fair judgement of tree health until the canopy has fully leafed-out in another month or so. If the tree's canopy looked normal last year and it didn't shed leaves early (though sometimes that's triggered by drought stress), then any serious damage from wood-boring insects is not as likely.

Miri

You're welcome!