The most common and most likely answer to this crossword clue is the 8 letter word HAMSTERS
I've seen this crossword clue in The Daily Telegraph
H
A
M
S
T
E
R
S
More clues leading to the result HAMSTERS
Buddy explains!
The straight part
We know that "pets" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case pets = hamsters.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does HAMSTERS mean?
HAMSTERS noun- Any of various Old-World rodent species belonging to the subfamily Cricetinae.
- Other rodents of similar appearance, such as the maned hamster or crested hamster, Lophiomys imhausi, mouse-like hamsters of genus Calomyscus, and the white-tailed rat (Mystromys albicaudatus).