snakes casting scare on my troops

[Vilk]

I don't think it's snakes that cast scare your troops, it's more probably some wolf on werewolf on their wolf form that used their wolf howl that scary human/elf/dwarf troops level 1&2. In this case you lost control of your scared troops when under the effect and sometimes they pass a turn and some other time they do something else.

There's few other cases where you lost control of your troops. For example randomly wolf or werewolf normal attack has a small chance to put the troop attacked in fury and next turn you won't control this troop.

If you use the dispel spell that removes all effects then you get back control of your troop or you can wait the effect expire.