From Creatures Wiki
 BHVR for Input
Syntax: BHVR binary_flags(int)
Sets the permissions of the current TARG to what you specify with 'binary_flags', this must be a single number that is the total of the flags you have chosen.
Creatures can do the following if the flag is used:
1 - Activate 1.
2 - Activate 2.
4 - Deactivate.
8 - Hit.
16 - Eat.
32 - Pickup.
 BHVR for Output
Used in place of a numeric constant or variable.
Returns the BHVR number of the current TARG.
ATTR being used in the command line to set the permissions of HOTS:
TARG HOTS BHVR 33
Being used in the command line to output the permissions of HOTS:
TARG HOTS OUTV BHVR