鳥たちが地面をつついている。

English Translation

Birds are pecking at the grounds.

How common is it for たち to be used with animals?

@cstuartroe

It’s common to use たち for animals especially when they are so adorable or worth to appreciate. For example, an animal/nature TV documentary video by NHK often narrates 鳥たちが, ペンギンたちが, 魚たちが, etc.