One of our readers came home after working a nightshift to find a clump of black creatures on his windowsill. He said the kitchen window was open, so that was probably the entry point for the specimens. Along with the photo, he sent us the classic request: “Can you tell me what these are?” He also wonders if they spread quickly.

The creatures are very tiny. In fact, they are so small that it is difficult to make out any other details of their appearances. We aren’t completely convinced about the identity of these specimens, but we do have some ideas.

It is very possible that these creatures are larvae, especially after considering their minuscule size. Two common types of larvae that could potentially be a match are drain fly larvae and pantry fly larvae. Drain fly larvae are quite identical to the specimens our reader found, but they typically inhabit drains, not windowsills. Pantry fly larvae, on the other hand, are found in kitchens (albeit, usually in stored grains in the pantry), but they are often cream colored, not dark. While either of these might be the correct identification, we still aren’t convinced. Since these creatures appeared only after the window was left open, we believe they probably came from outside, not from the pantry or the drain.

There are various other types of larvae that could be a match. Unfortunately, we don’t know for certain what these worm-like organisms are. We think our reader should focus on getting rid of these creatures. Since they are gathering in one spot on the windowsill, we assume there might be some potential food source that wasn’t properly cleaned up. Our reader should wipe down all of his windowsills and counters to eliminate any other potential food sources. Now on to his next question: Will these creatures spread throughout his house? We don’t think so. Since we weren’t able to determine the species, we don’t know what they eat or will be attracted to inside a home. However, we think that as long as our reader keeps his home clean, these specimens won’t travel far beyond the windowsill.

In summary, we weren’t able to identify the black creatures on our reader’s kitchen windowsill. We think they are probably some type of larvae.