Them!

FBI agent Robert Graham sets out to inquire about a strange occurence that has happened in the desert of Alamogordo, New Mexico. The autopsy of a victim reveals that its body contains enough formic acid to kill 20 men! Helped by two famous myrmecologs, Professor Medford and his daughter Patricia, Graham departs into the desert in search of new evidence. There they discover a footprint. For the professor, there is no doubt that it is an ant footprint. The 12cm length of the imprint indicates that they will have to deal with ants of a size of a house!