Summon nature's ally spell mentions:
This spell summons a natural creature. It appears where you designate and acts immediately, on your turn. It attacks your opponents to the best of its ability. If you can communicate with the creature, you can direct it not to attack, to attack particular enemies, or to perform other actions.
A summoned monster cannot summon or otherwise conjure another creature, nor can it use any teleportation or planar travel abilities. Creatures cannot be summoned into an environment that cannot support them. For instance, a porpoise may only be summoned in an aquatic environment. The spell conjures one of the creatures
from the 1st-level list on the accompanying Summon Nature’s Ally table. You choose which kind of creature to summon, and you can change that choice each time you cast the spell. All the creatures on the table are neutral unless otherwise noted.
I am guessing since the purpose of this spell is for summon to fight, we don't need to roll a "handle animal" check to get them to attack a target. What happens if you want them to do something else other than attack such as guard or interact with an object? Is this possible for a summon to do?