the 2th 3th 4th milestones wath are they?

The second milestone is building a dam. You have to have upgraded construction and then drag a builder to the right hand side of the map where it says the stream is barely covering here or something like that. The third is building a scarecrow to get rid of the birds that are eating your crops. Drag an expert farmer to the place where it says there are sticks and vines. The fourth is building a sharp tool (needed for clearing the vines.) To do this, upgrade exploration then drag a scientist to a place to the right of the vines where there will be small black sharp things and bendy sticks. They will use these to build a sharp tool. If you have anymore questions you can email me ([email protected]). Hope this helps

Puzzle #2: This puzzle is the completion of the dam in the pond on the shallow end.. You must purchase level 2 of Engineering. Drop your builder/builders in the pond, and they will begin building the dam.

Puzzle #3: Building of the scarecrow. "The Birds" will attack and destroy your crops after the first crop. You must get this scarecrow built as soon as possible. Level 2 of Engineering is required. You may use either an adept farmer or a master farmer. Just behind the research hut/table, you will see twisted vines. Drag your farmer to the vines. The building of the scarecrow requires two trips to this area. The farmer will pick up some of the vines. The action will read, "Building a scarecrow". The farmer will carry his vines to the crop, and erect it at the north end of the crops. Pick him up once again, and drag him back to the vines. He will again pick up vines. He will returns to the crops and complete the scarecrow. You are now safe from "The Birds".

Puzzle #4: The Cutting Tools. After purchasing level 2 of Exploration, several objects will appear that you could not see before. Only adults can see these objects. There is no action if you use a child. Back behind the research table just to the right of the blue rose/flower you will now see a whitish colored stone with three dark gray or black vertical lines on it. Select a master scientist and drag them to the area of the stone. They will bend down and pick something up. Action will read, "Building cutting tools". The scientist will return to the research area. Grab the same scientist and drag them back to the vines found in the same area behind the research table. They will pick vines to use for handles for the construction of the cutting tools. You will see the tools appear in the upper left hand corner of the hut, leaning against the hut.

In puzzle 2 they don't have to be builders!
I just put tons of people on but tick the builder box, it works natrally