Are Weasels Loners?

Question

For the first time in 30 years, I spotted a Weasel (Lesser Weasel, I think) on my property, and birds and chipmunks began to disappear .

I trapped it and listened to it sing "Born Free" as I released it deep in the forest.

Are they loners, or can I expect that he/she wasn't alone, and there will be more of his pack or family?

Answer 1

Except for mothers with young, yes, weasels are solitary. They do not live in groups or even male-female pairs.

Answer 2

No, but they will lease when pressured.

I believe that they will group in a small family, but are otherwise not a social animal.  There are collective terms for them though, which include gang, pack, and confusion.