If you find a reddish-brown beetle about 1/8" long in spices, which beetle is it more likely to be?

The reddish-brown coloration and size of approximately 1/8 inch strongly suggest that the beetle in question is likely a cigarette beetle. This beetle is commonly associated with food products, particularly stored products such as spices, tobacco, and dried foods. Their size and coloration fit the description provided precisely.

The cigarette beetle typically has a smooth body and is slightly elongated, which also helps in identifying it among other beetles. When found in spices, it's known to infest not just tobacco products but various dried goods as well, making it a frequent pest encountered in food storage areas.

While options like the red flour beetle, drugstore beetle, and rice weevil also have associations with food products, their distinct characteristics set them apart. The red flour beetle is typically associated with flour and grains and is generally brighter red in color. The drugstore beetle, although similar, is more oval-shaped and has a slightly larger size. The rice weevil tends to be darker and is specifically associated with whole grains, having a more pronounced snout.

Therefore, given the size, color, and typical habitats of these beetles, identifying the specimen as a cigarette beetle aligns best with the provided details.