Can I get some assistance from an expert? We have an influx of pixies at our house.

I know by the little gifts they deposit around, gifts from nature's shopping center. I just need to know the etiquette - does one put out food and drink, or figure out a return gift, or knit little sweaters? The hubs would not believe this and i need to learn what's the correct protocol so's not to offend. Can't piss off the pixie population!