OK. First I tried Gordon's method:

<snip
Sub Ant_Killer()
Application.CutCopyMode = False
End Sub

To create a General Module, hit ALT + F11 to open the Visual Basic Editor.

Hit CRTL + r to open Project Explorer.

Find your workbook/project and select it.

Right-click and InsertModule. Paste the code [given above] in there.
Save the
workbook and hit ALT + Q to return to your workbook.

Run or edit the macro by going to ToolMacroMacros.

You can also assign this macro to a button or a shortcut key combo.
</snip

I had no luck with that. Tried it twice from scratch and the ants remain
after pasting, then disappear in the process of clicking thru
Tools/Macros/Macros (or pressing Alt+F8 to open the macro window). So I
must be missing something. I didn't see the point of setting up the
macro when just trying to run the macro does the job the macro was set
up to do.

Next I tried Simon's method of pasting

Private Sub Workbook_SheetChange(ByVal Sh As Object, ByVal Target As Range)
Application.CutCopyMode = False
End Sub

into ThisWorkbook.

That worked great, except if you want to paste the same source formula
in multiple cells you have to recopy the source each time, paste,
recopy, paste, recopy ... So this one actually works too well.

T.Valko/Biff's Toolbar method that'll work on all files - I must have
missed it because I didn't see that method actually explained anywhere
to try it.

So, I think Andrew's Escape method or Suleman's Enter method will work
best for me as I can paste multiple times then just hit Escape or Enter
after making the last paste. Escape is easier for me to reach on the
keyboard, so that will probably be the one that works its way into my
habits.

Thankyou everyone,

RC