The functions 'Select all units' 'Select all ground units' 'Select all units on Screen' 'Select all ground units on screen' all do not also select skitters, this is annoying as I have to redouble my selection of units to add them in.
Non-combat units like Skitters and Engineers are usually excluded from Area selection. There are exceptions (like them being the only thing being selected). Ctrl+Z can be used as "select all units on screen whose type fit's at least one of the units I already have selected".
This issue is in the bugtracker, waiting for a fix. FS#4046 - Select all land units (hotkey) doesn't select AA tanks And of COURSE the anti air vehicle should be selected with tanks and inferno's, they are an essential part of a land unit based army.
This thread was about Skitters (the land scout) not being selected. It was not about Spinners (the AA) not being selected.
Woops sorry yeah, I'm so annoyed by spinners not being selected I misread it as spinners The land and air scouts not being selected is actually good I think, send armies around without accidentally cancelling your scouting units.