I'm occasionaly came across the phrases:

• "sitting still";
• "standing still";
• "laying still";
• etc.

For most cases the usage is clear (humans for example). But sometimes it is not clear what verb to use with "still":

• for an spherical objects - I have no idea;
• birds - I think they are "standing";
• fish - again, no idea;
• and so on.

Is there any advice on how to choose an appropriate answer?

I'm occasionaly came across the phrases:

• "sitting still";
• "standing still";
• "lying still";
• etc.

For most cases the usage is clear (humans for example). But sometimes it is not clear what verb to use with "still":

• for an spherical objects - I have no idea;
• birds - I think they are "standing";
• fish - again, no idea;
• and so on.

Is there any advice on how to choose an appropriate answer?