comma

[mengta]

In fact, the members of this family of insects exhibit a wide range of social and solitary behaviors. Aggression varies from species to species, and also varies within each species depending on the individual's role within the larger social grouping.
does it need a comma before 'depending'? does the meaning of the sentence change if i add a comma before 'depending?'
thanks

[Casiopea]

If the present participle phrase modifies a noun all the way at the beginning of the sentence and there is another noun between, you should probably use a comma.

EX: I sat down near Jerry, thinking that the ground was dry.

EX: Mrs. D'Amico was in the front yard, trimming plants.


Notice the difference here:

[1] The mayor took us through the city, explaining all the sites.
[2] The mayor sold us a guidebook explaining all the sites.

Source

[Coffa]

If the present participle phrase modifies a noun all the way at the beginning of the sentence and there is another noun between, you should probably use a comma.
EX: I sat down near Jerry, thinking that the ground was dry.
EX: Mrs. D'Amico was in the front yard, trimming plants.
Notice the difference here:
[1] The mayor took us through the city, explaining all the sites.
[2] The mayor sold us a guidebook explaining all the sites.
Source

That means 'yes', and 'yes' .

[mengta]

she was running back home crying.
she was running back home, crying.

so i need a comma here?
thanks

[Casiopea]

she was running back home crying.
she was running back home, crying.

so i need a comma here?
thanks

Yes, and even thought we know that homes can't cry, consistency is important, so a comma is recommended.

Note, The participle modifies the noun it is right next to; if there’s any interruption (a comma), it modifies the next earlier noun.