Dense

 (High Density in 4.1) is the thirty-seventh offline mission and the fourtieth online mission in Earth Defense Force 2025 and the thirty-eighth offline mission and the forty-first online mission in Earth Defense Force 4.1: The Shadow of New Despair.

Objective
2025: The alien mothership has been destroyed. The coordinated attack resulted with two motherships defeated. The Ravagers will be in shock after this turn of events. However...since then the giant bugs have gone to nest and are multiplying. A tunnel entrance has been discovered at the port area. Although we have beaten back the Ravagers, we cannot rest until these evil spawn are destroyed. We will destroy the underground tunnels.

4.1: The alien motherships have been destroyed -- two of them! The Ravagers will be in shock after this turn of events! However... many of the giant insects have gone to nest and are still multiplying. A tunnel entrance has been discovered at the port area, and although we've beaten back the Ravagers, we cannot rest until these evil spawn are all destroyed! We must clean out the underground tunnels.

Storyline
Storm Team and two Ranger teams arrive to the port and HQ orders them to destroy the Tunnel Exits. The Aurora Situation Report reporter with the bad microphone reports that the EDF destroyed three Motherships in North America, Japan and Europe and says that it was half of the Ravagers' force, confirming that the two previously damaged Motherships must have been pulled back before they could attack Earth.

While she does her thing, Tunnel Exits start appearing around the port's loading area and the soldiers engage the giant insects coming out from them. Eventually the Tactics Officer reports that Pale Team heading there and HQ explains that they are an elite Wing Diver unit who just killed Retiarius showing that he still doesn't know that the plural of Retarius is Retiarii. Ohara then tells that the Wing Divers are excellent at fighting giant insects, something that have been repeatedly told since the second mission. Of course, everyone knows already and they ignore him, so he repeats himself, but after he sees that he's not getting any reaction he shuts up.

Storm Team eventually destroys the last of the Tunnel Exits and the mission ends.

4.1 Changes
The name of the mission was changed to High Density.

The number of enemies was increased drastically and a new wave was added. Instead of the 6 Tunnel Exits of the original there are now 32 of them (although one doesn't seem to work so it's effectively only 31). The number of insects spawning is more than 4 times more than the 2025 version with even more on harder difficulties. On Inferno mutants will also appear.

Instead of the two Ranger teams, Storm Team is aided by one Ranger and one Fencer team.

This mission seems to be led by the Tactics Officer since she is the one who orders the attack instead of HQ and she also warns the soldiers when the second wave starts.

4.1
Bring a weapon to deal with the swarm of insects and a high-damage weapon against the Tunnel Exits preferably not explosives since the map has some great cover that explosions can destroy.

Since anthills spawn far away and the bugs won't attack until angered, you can snipe the tunnels from relative safety and only have to worry about the insects near your current target.

The stacks of containers make great cover, since the gap between them is too narrow for the bugs to properly attack you. On the other hand you won't always have a proper line of sight either. Weapons that can shoot through corners like the Wing Diver's electric weapons are excellent here. During the second wave one of the Tunnel Exits doesn't work for some reason. It can be found on the right side of the main road, behind a warehouse just after the second crossroads. Try to save it for last so you can collect the loot in peace. Be careful when the NPC soldiers will follow you as they will try to destroy it. You might want to kill them or make them follow you into the water.

Both Versions

 * The mission's description was mistranslated in the English version. Originally it says that the Japanese branch of EDF destroyed their Mothership while other countries destroyed two more. However the English translation of 4.1 states that only two were destroyed altogether. The 2025 version can be interpreted either way, since it states that two mothership was destroyed world-wide, but it isn't clear whether that includes the one in Japan or not.