Are Squirrels Diurnal? Tree Squirrels Yes, Flying No

Tree squirrels are strictly diurnal. Out at first light, busiest at dawn and dusk, back in the drey before dark. Flying squirrels are the exception and are strictly nocturnal.

The daily pattern

The two peaks are a predator trade-off. Low light at dawn and dusk gives some cover from hawks, which hunt by sight, while full darkness belongs to owls and the squirrel’s own eyesight is poor in it.

Seasonal shift: in high summer the midday gap widens and the peaks move further apart. In winter the pattern compresses into one middle-of-the-day session, because the days are short and the cost of being out in the cold is high.

Flying squirrels are the exception

Southern and northern flying squirrels are common across much of their range and almost entirely unseen, because they are out between dusk and dawn. People living with them for years often have no idea.

Why it matters for exclusion

Knowing greys are diurnal makes two practical jobs easier:

Finding the entry point. Sit where you can see the whole roofline at dawn and watch them leave. Twenty minutes at first light finds in one go what hours of ladder work often miss.

Timing the work. Fit a one-way exclusion door during the day, while the animals are out foraging. Sealing a roof at night with greys inside is how an animal gets walled in — and if it is February to April or August to October, it may be a nursing female with kits.

Winter, and what is not hibernation

Tree squirrels stay active all year. They have:

• Cached food — the autumn burying is the entire winter plan
• A denser winter coat, including the pale ear fringing
• A modest fat layer
• Shared dreys — two or three animals huddling for warmth

In genuinely severe weather they may stay in the nest for a day or two. That is waiting it out, not hibernation, and they come out as soon as it breaks.

Ground squirrels, marmots and chipmunks are different animals in this respect: chipmunks enter long torpor with periodic waking, and ground squirrels and marmots truly hibernate. That is part of why chipmunk activity in a garden stops abruptly in autumn while squirrel activity does not.

A squirrel out at night

Usually means something happened:

• Disturbed from the drey by a cat, raccoon, owl, or building work
• Displaced after a tree came down
• Unwell — including head injury or rodenticide poisoning, both of which produce slow, disoriented animals that are unafraid

Do not approach one. If it is staggering, circling or unresponsive, call a licensed wildlife rehabilitator and keep pets away from it.