Baya is fascinated by berries and how they all taste different and have different effects when eaten. She also likes to watch people during the day when they are outside and judges those she likes, that are good or she finds funny. Then during the night, she sneaks into their rooms with the help of her bio-luminescent speckles that glow the way(due to her colouration type) and places berries everywhere. 
The better the berry the more she likes you! 
But when she is feeling particularly sneaky or cheeky she hides rotten or nasty berries for those she doesn't like, or just for the fun of it. 
She finds it fascinating too, that people are like berries, some are sweet and some are sour and some are just plain bitter. Even though sometimes they look so similar. 

Baya doesn't really have any goals, she's pretty content with living in her Mulberry tree doing what's she's doing, watching, laughing and occasionally playing with other Sugernixs. 
She does have a dream, but it involves large masses of pie, jam and the biggest berry in existence...
Or maybe she hopes some night she will get caught hiding the berries and be able to give them in person instead of always sneaking and hiding.