Entry Point Self-Inspection Checklist
Walk your house with the same list an exclusion inspector uses. Ground and binoculars only, no ladders needed: every item below is visible from the yard, and the point is a count and a map, not a repair session. A bat fits through a gap of about 3/8 inch, so you are hunting tells as much as holes: staining, smudging, droppings, and dusk activity.
Work through each zone and mark every point either clear or flagged. Your counts update here, and the summary tells you what the results mean.
The roofline
Best checked from the ground with binoculars at two times: bright daylight for gaps and staining, and the half hour after sunset for bats actually leaving.
Look where the ridge cap meets the shingles at each end of the peak. Dark smudge marks or staining at a gap are the classic sign of an active bat entry.
Torn, bent, or missing screen behind the louvers is a wide-open door. Droppings stuck to the louvers or a stain running down the siding below means it is in use.
Where a lower roof meets a wall, or a dormer meets the main roof, flashing pulls open as houses settle. Check the corners of every junction for daylight-sized gaps.
The boxed corner where soffit meets fascia at a roof edge is a favorite squeeze point. Sagging panels and lifted corners count even when they look small.
The chimney
Chimneys collect three different problems: bats in the gap beside the masonry, raccoons down an uncapped flue, and birds behind loose flashing.
The metal joint where masonry meets roofline. Lifted or separated flashing leaves a channel into the attic that bats use and squirrels widen.
No cap, or a damaged one, invites raccoons and chimney swifts. Chimney swifts are federally protected migratory birds, so an occupied flue in summer waits for the young to leave, exactly like bat maternity season.
Walls and penetrations
Everything that passes through an exterior wall made a hole when it was installed. The question is what has reopened since.
Cable, electrical, HVAC lines, and exterior faucets. Old caulk shrinks and drops out; a gap the width of a pencil is enough for a bat, and mice need less.
Vinyl and aluminum corner posts are often open at the top behind the J-channel. Check where trim meets siding for separations and stains.
Bathroom, kitchen, and dryer vents with broken flappers or missing screens. Birds love dryer vents; bats use static attic vents with damaged screening.
Ground level
Bats rarely enter low, but the dead-animal-in-the-wall story usually starts down here with rodents and the occasional opossum.
Where siding meets foundation, especially at corners. Gnaw marks, rub smudges, and tunneled mulch are rodent tells worth taking seriously.
Bent frames, missing screens, and doors that no longer seat. An open crawlspace is how animals end up dying under the one room you cannot reach.
The evidence pass
Signs beat holes. If any of these are present, treat the house as active and get an inspection regardless of what the gaps look like.
Bat guano looks like dark rice grains, accumulates in piles below the entry and in the attic below the roost, and crumbles to dust when dry. Do not sweep or vacuum it dry; that is the histoplasmosis scenario. Note it and leave it for the cleanup crew.
Body oils from repeated squeezes polish a dark, greasy halo around an active entry. It is the single most reliable visual tell on the list.
Stand where you can see the suspect side of the roof starting 10 minutes after sunset and watch for 30 to 40 minutes. Count what leaves and from where; that count is gold to whoever does the exclusion.
Bats are loudest right before emergence and at return. Daytime scurrying points to squirrels instead; nighttime gnawing points to rodents. The timing of the sound is diagnostic.
Safety notes, honestly meant: stay off ladders for this, never handle a bat bare-handed, and never disturb droppings dry. If anyone may have had direct contact with a bat, call your local health department first; the CDC explains why at cdc.gov/rabies. And do not seal anything, even an obviously open gap, until you are sure nothing is living inside; our season checker explains the timing side.