SELECT T3.service_id ,  T4.Service_Type_Code FROM participants AS T1 JOIN Participants_in_Events AS T2 ON T1.Participant_ID  =  T2.Participant_ID JOIN EVENTS AS T3 ON T2.Event_ID   =  T3.Event_ID JOIN services AS T4 ON T3.service_id  =  T4.service_id GROUP BY T3.service_id ORDER BY count(*) ASC LIMIT 1
Which service id and type has the least number of participants?
[Schema (values) (types)]: | local_govt_in_alabama |  Services : service_id (text) , service_type_code (number) | Participants : participant_id (text) , participant_type_code (number) , participant_details (text) | Events : event_id (text) , service_id (number) , event_details (text) | Participants_in_Events : event_id (text) , participant_id (number);