Tricks from the Bag of Tricks
So, the description for Bag of Tricks says:
You can take a Bonus Action to command how the creature moves and what action it takes on its next turn, such as attacking an enemy.
The rules refer to them as creatures, not spirits in animal form such as familiar or the animals called up by Conjure Animals. Given this, the animals would have limited ability to understand any orders given. Nevertheless, one could rely on any of these animals to perform simple tricks first outlined in 1E, such as having a rat or weasel bring to you the cell keys from a peg on the wall or commanding a dire wolf or brown bear track a scent.
Returning to the rulebooks, it was indicated that an animal could be trained to perform up to three tasks/tricks per point of intelligence the creature possesses. If one is not going to have them to simply provide extra bodies on the battlefield, would you state that the animals already know how to follow the simple commands or that they automatically know how to perform 1-9 of the tricks outlined in the rules?