Gather as much information from Biff and Dusty on the first day, but if you've got the information from previous games then don't worry, as it doesn't change. Get into your car and go to the KBUG radio station. Dusty will tell you of the latest ant attack to occur and will give you a Geiger counter and a gun. Hang around for a while until the afternoon, then go round to the Platt University lab, where you will meet the boy Billy and his rather strange father. When they start talking to you, ignore the gibberish that his dad speaks but listen carefully to what Billy has to say. If you want further information then try asking the fortune tellers and expect to get home around eight o'clock.
Go out to the KBUG radio station again, where Dusty will tell you about a threat from the G-men. Go back to the lab afterwards, where Billy once again provides some useful information. At about one o'clock go to Neptune Hall, where you'll find that Billy Bob has managed to sprout a rather fetching set of antennae. Pull out your gun and blast his antennae off. When he comes around he will give you an important number, so make a note of it.
You should wake up at nine o'clock when Jakie comes round and knocks on the door. Unfortunately, your early morning visitor is one of the Ant- heads, so get the trusty old gun working and write down the number again. Go to the Ore Plant and befriend the manager by selecting choice A at the appropriate time. Take the train to section M-3 and do the business against the ants, then get back to the lab for some more useful info from Billy. Go to the Police Station and get the old 'he must have tripped on his shoelace, your honour' treatment so you get knocked unconscious. When you wake up, the nurse will give you the position of the vault. Go to the vault and get the records containing the conversion process, then make a run for it.
Drop by Elma's and when he becomes an Anthead blast his stalk to get the last number. Now you have all three numbers, try and get into the hospital any way you can (preferably without injury). Get the lift to the basement and find the morgue in the top right-hand corner - you can spot it by the four black slabs and the safe. Enter the numbers in the order you recieved them and you should be able to get the secret documents which will cause the realisation of the Antheads' existence, so now you can take them on face-to-face.