Hollow Knight Silksong The Lost Fleas Quest Guide

From the very start of Hollow Knight: Silksong, exploration is incentivized not only in terms of shortcuts and secrets, but some truly way-out side quests that add depth to Pharloom's weird inhabitants. Near the top of this list is the first and most important of these, the Lost Fleas quest in Silksong, a pick-up-style mission in which Hornet must track down and rescue a group of small but delightful creatures that are spread out over several different areas.

In practice, the quest is simple: locate five lost fleas and bring them back home to safety. On the surface, you'd dismiss it as yet another sideline activity, like the Grub rescues of old-school Hollow Knight. Silksong's Lost Fleas quest is something more. Not only is it something that can be accomplished fairly early in the game, but it also provides you with one of the most important boss fight items, something that can be the difference between success and failure in difficult battles.

Here in this guide, we'll walk through step-by-step how to unlock the quest, outline where the Lost Fleas are in Silksong, take you through each location step-by-step, and highlight the reward that makes it so worth the hassle. If you're looking to level up Hornet early in the opening acts of the game, you'll want to prioritize this quest the moment you reach the Marrow.

Unlocking the Lost Fleas Quest

You will first get the quest shortly after you leave Bone Bottom. Press on into the Marrow zone and simply continue to explore until you discover the Flea Caravan, a nomadic caravan of tiny insect-people led by the Fleamaster Mooshka. This caravan unlocks the quest chain for you. It is not a problem to get to the Flea Caravan. From the Bone Bottom entrance, take the upstairs platforms to the right until you reach a room going vertically. Go downwards, and you will soon be in a room where Mooshka, Grishkin, and Varga have sat around a bench.

Speak to Mooshka, and he'll explain the problem: some of their beloved fleas wandered off and are now lost somewhere in Pharloom. They need your help to herd them back. Securing his request unlocks the Lost Fleas side quest in Silksong, filling the world with flea locations just waiting to be discovered. Most notable is the fact that there are more than five fleas total, fifteen, to be precise, but you can only rescue five to complete the quest. That's the wiggle room that allows you to organically work on the mission while you're hunting for Pharloom, without having to round all of them up right away. Rescuing five in a hurry is highly recommended, however, as the reward makes a significant difference in boss fights.

Tips for Finding the Lost Fleas

The fleas aren't just out in the open. They're typically trapped in cages, bound up in vines, or otherwise hidden in map corners. To make it even worse, they're usually surrounded by enemies, so you have to fend off tiny ambushes before you can free them. Fortunately, there’s a reliable way to track them down: listen closely for their cries or snores. Much like the trapped Grubs in Hollow Knight, the Lost Fleas make distinct sounds when you’re near their location. Using headphones can make this easier, especially in noisy regions where environmental sounds might mask their calls.

The Lost Fleas Silksong Locations

Here are the initial five flea locations you can reasonably discover as you move through Act 1. These are some of the earliest opportunities to complete the quest.

The Marrow

Your first flea is located pretty near the Flea Caravan itself. Head right from where you defeated the Bell Beast, into a really large open room. Pull the lever to open doors, then head up the platforms to the top and into the room above. Inside, you’ll face a platforming challenge combined with aerial enemies. The flea is trapped in vines at the far upper-right corner, but you’ll need to circle around from the left side of the chamber to reach it. Be patient, this one might take a few tries if you’re still learning Silksong’s tighter platforming mechanics. Once freed, the flea scurries off in safety.

Deep Docks

Your second flea is related to your progress in the Deep Docks. After gaining the Swift Step dash capability, return to the room where you got it. Instead of leaving, use your new mobility skill to dash to the higher level of platforms in the room. Up top, there's another flea trapped in strange black eggs. Free it, and you will have rescued your second lost friend.

Hunter's March

The third flea is on the door to Hunter's March, a little side optional area off the Marrow. To get there, you will first have to kill a Skarrguard, a mini-boss that roams around. He is in a room above the Marrow prison, where you first encounter Grindle. With Swift Step, the Skarrguard is a breeze to manage, but his strikes have some heft. When he's defeated, navigate through his arena to Hunter's March. Continue along the platforms, jumping on the red buds to ascend through the spikes, until you come to a cage that contains the flea. Free it, and you've completed three, with two to go.

Far Fields

The fourth flea is in a hidden room in the Far Fields. Head to the right of the Deep Docks entrance until you find two red ants standing by a lantern. Kill them, then use the clear space to jump up onto higher platforms and head to the top entrance. Inside, move to the far right, where you’ll discover a destructible wall. Smash through to reveal a secret area, then continue until Hornet is suddenly trapped in a cage. Break free, defeat the red ant ambusher, and move further right to find the flea imprisoned nearby. Freeing it adds another tick toward completing the quest.

Shellwood

The fifth flea requires patience and skill because it's located in one of the more challenging platforming gauntlets. You'll require the Drifter's Cloak so you can do a glide to access it. The starting point is Shellwood's middle chamber, where you previously found Shakra, and go right, using white roses as springboards to get across gaps. Head upwards when you reach a forked path. You will then be forced to slide down through a spiked vertical shaft and hostile flowers. Move slowly through until you reach the bottom, where the final flea is waiting to be rescued.

The Reward for Rescuing the Lost Fleas

Having rescued five fleas, return to the Flea Caravan in the Marrow and speak to Mooshka. He'll ask you to join them on their travels, which will bring you into a cutscene that relocates the caravan to Greymoor, outside of the Halfway Home tavern. There, Grishkin provides you with the Flea Brew, which is a strong beverage item. If you consume it, Hornet becomes faster in moving and attacking, and you're much better at fighting. Those nasty boss fights, which are notorious in Silksong, are easier and quicker if you're striking faster and dodging cleaner.

Better still, the Flea Brew can be refilled for free by returning to the caravan and speaking with Grishkin again. That gives it an infinitely renewable status and one of the greatest rewards you can gain so early in the game.

Why You Shouldn't Skip the Lost Fleas Quest

To most players, the side quests are easy to postpone until the very last minute, but the Lost Fleas quest in Silksong is among the few that you're rewarded for immediately. If you complete it in Act 1, you get an item that affects combat difficulty right away. Even the hardest bosses are more bearable with more attack speed, and the improved movement allows you to live longer in places that are chock-full of peril. Equally important is the charm of the story. The Flea Caravan instills some personality in Pharloom, and reuniting them with their lost family members makes the world feel more alive. It's a quest that combines heartwarming character moments with concrete gameplay rewards.

Final Thoughts

So, where are the Lost Fleas in Silksong? They’re scattered across regions like the Marrow, Deep Docks, Hunter’s March, Far Fields, and Shellwood, hidden in cages and guarded by enemies. By carefully exploring, listening for their cries, and braving tricky platforming sections, you’ll be able to free five and complete the quest. The payoff, entry to the Flea Caravan's new camp, and the endlessly replenishing Flea Brew are some of the most rewarding early-game quests. If you want an easier boss fight experience and a rewarding side quest that gives context to Pharloom, do it. Prioritize searching for Lost Fleas Silksong locations as soon as you can.