Carpenter ants do not eat wood and cannot chew sound heartwood. They hollow galleries in wood already softened by moisture and decay fungi. Their presence tells you a decay pocket exists inside the trunk, usually larger than it appears from outside, and that it stays wet. The ants are tenants, not the cause of the damage — but they are a dependable indicator that the interior is not solid. In Carmel — Village of WestClay, Brookshire and Woodland Springs included, that's normally a hazardous tree removal job at $800–$5,000. Within weeks.
Why this comes up in Carmel
June 29, 2023 derecho — Carmel logged several medium-sized limbs down while the same line measured 70 mph at Indianapolis International. The July 15-16, 2024 derecho tracked directly through Hamilton County with damage at Westfield (about 55 mph), Cicero and Atlanta, including a barn hit by a gustnado near Atlanta. September 14, 2008 remnants of Hurricane Ike brought 50-70 mph gusts for hours across central Indiana.
Carmel's canopy
Carmel Urban Forestry publishes an approved species list (last revised 3/28/2024) whose "Undesirable Trees" section reads like a field guide to what fills older Hamilton County streets: silver maple (shallow roots, weak wood), Callery pear, pin oak, red maple and all Fraxinus for emerald ash borer. Approved large street trees run to swamp white oak, bur oak, chinkapin oak, hackberry, male-only ginkgo, thornless honeylocust, Kentucky coffeetree, baldcypress and London planetree; note Callery pear is discouraged locally but is not yet banned in Indiana — 312 IAC 18-3-25 currently lists 44 species without it.
Hamilton County rules
Carmel's code section 6-64 is titled "Planting and Removal of Trees and Shrub Regulations" and sits in the streets-and-sidewalks division of Chapter 6, alongside 6-55 covering trees and shrubs that obstruct streets and sidewalks — so the city's active regulation is aimed at the public way, plus landscape and buffer plantings approved through development plan review by Urban Forestry. I could not verify the exact text of 6-64 or confirm whether any permit applies to removing a tree standing entirely in a private back yard; contact Carmel Urban Forestry through the city's Department of Community Services before assuming, and check HOA covenants, which in most Carmel subdivisions are stricter than the city.
The tree lawn in Carmel
The strip between sidewalk and curb is city right-of-way, and Carmel Urban Forestry plants and maintains the street trees in it, including species selection. Many Carmel subdivisions layer a platted landscape easement and HOA covenants over that same ground, so two approvals can apply to one tree.