Found this mucking around, it is one I haven't seen before and can't find any info here for the UA:
220.127.116.11 - - [21/Jan/2013:17:26:57 -0600] "GET /products/ HTTP/1.1" 200 27445 "http://www.example.com/?s=blue%20widget"
"ZTE-Z431/1.4.0 NetFront/4.2 QTV5.1 Profile/MIDP-2.1 Configuration/CLDC-1.1"
The search almost makes it look human, but the files requested had nothing to do with the query and the refering directory only URL does not exist.
32 files in under 2 minutes. ARIN gives me:
18.104.22.168 - 22.214.171.124
Service Provider Corporation
That range seems very broad to me. (?)