Old MacDonald's nursery rhyme paints a delightful picture of farm life for children and teaches parents a textbook way to incorporate melody into itemized deductions. Experience farm fun for all ages with today's Groupon to Lemos Farm in Half Moon Bay. Choose between the following options:

• For $20, you get day passes for two children and two adults (a $40 value).
• For $50, you get $100 toward a birthday party.

Lemos Farm’s three-generations-old ranch―festooned with seasonal decorations―hosts outdoor activities for parents and children. Day passes grant access to numerous excursions on the train and pony rides, as well as unlimited attendance at the petting zoo for an introductory course in farm-animal massage therapy. On the weekends, laser-tag combatants maneuver through the sun-basked field to blast one another with photons traveling at the speed of light during 20-minute matches. Youngsters can also grip the levers on the hydraulic-powered Dig Zone tractor to displace dirt and build lavish sandcastle subdivisions.

Lemos Farm entertains birthday gatherings with two different themes that cater to celebratory groups of 20 children or fewer. Pony-party ($275+) invitees can frisk fur by saddling up on one of four ponies meandering about the petting zoo, and choo-choo party ($275+) denizens can park posteriors on an industrial stallion during unlimited rides on the John Deere–powered train or can redeem 1 of 15 tickets for pony rides. Both parties reserve romps in the air jumper and play structures along with a seat in the picnic area, an ideal place to grill a coming-of-age meal and blow out confectionary fire hazards. Lemos Farm’s festivity experts also give celebrators the option of nonprivate party rentals ($30 site rental) with day passes available for purchase for all guests.